Last partial update: September 2019 - Please read disclaimer before proceeding

 

Why is this section so important?

The child - The First 1000 Days

The first 1000 days of a child's life, from conception till the age of 2 years, is the most important time in a child's development and optimal care during this time will help prevent negative health outcomes from:

Many adult illnesses are being parially linked to the child's first 1000 days, including heart disease, stroke, obesity, allergies, diabetes, cancers and mental health problems, such as schizophrenia. (The brain is closely linked to other key body systems.) It also influences how well they are likely to do at school, their social and emotional outcomes and their ultimate 'adult outcome', including earning ability.

The graph below highlights just how much illness in children originates in the first year of life and much of this is te result of conditions that occur during pregnancy and at child birth. It is the time where things need to go well.

 

Source: Adapted from Australian Institute of Health and Welfare: 2015.

The parent relationship

The decision to have children is a fundamental turning point in the life of a couple. Relationships until this time are something that can be walked away from; albeit with some considerable psychological, social and financial trauma. This is much more difficult after having children. It is the time when in life when a person makes the decision to place themselves second for the long term. It requires thought and planning.

The First 1000 Days

The first 1000 days of a child's life, from conception till the age of 2 years, is the most important time in a child's development and optimal care during this time will help prevent negative health outcomes from:

  • maternal stress and poor nutrition during pregnancy (including maternal folate and iodine deficiency)
  • maternal smoking and alcohol use
  • parental abuse and neglect
  • maternal infections
  • unstable home environments

A common misconception is that the expression of your genes and your brain development is predetermined. There is very good evidence to show that this is not the case and that the way your genes are expressed is significanctly determined by interactions iot has with its environment, especially the factors mentioned above. Importantly, this process starts occurring in the foetus as the developing embryo tries to manipulate its genome's expression to best cope with the environment it is exposed to in the womb (and that it thinks it will be exposed to after birth. This ability to adapt is termed plasticity. These changes to the genes can persist throughout life and importantly can be transmitted to developing eggs in female ovaries. This means that these genetic changes that develop in utero, termed epigenetic changes, can even be transmitted to future generations. Ensuring good health in pregnancy is a multi-generational responsibility.

An example of the type of change that can occur is alterations to the length of protective 'caps' at the end of genes / chromosomes called telomeres. Shortening these can influence the health of the gene and its functioning lifespan in the body.

This ability to influence development (plasticity) is even more prevelent in the development of the mind-boggingly complex interconnection between brain cells. The brain is closely linked to other key body systems and these connections are favourably developed when beneficial stimuli are experienced and are reinforced when these stimuli are repeated. The opposite is also the case. Unhelpful connections can be partially reversed later in life but this becomes more difficult with time and complete reversal is often not possible.

Many adult illnesses are being parially linked to the child's first 1000 days, including heart disease, stroke, obesity, allergies, diabetes, cancers and mental health problems, such as anxierty and depression and even schizophrenia. (The brain is closely linked to other key body systems.) It also influences how well they are likely to do at school, their social and emotional outcomes and their ultimate 'adult outcome', including earning ability.

Further reading: The First 1000 days

 

The decision to become pregnant

Pregnancy is one of the most important periods in any relationship. It is a time of huge change that is unavoidably associated with increased stress. To help ensure each pregnancy is the happy and fulfilling experience that it should be, it is very important to prepare for the event properly. This includes making an active decision to become pregnant and discussing the many medical, social, vocational and financial issues involved in having a child. It has been shown that a stable home environment has a huge imact on the development of infants and older children.

With regard to medical ‘preparation’, much important foetal development occurs in the first 17 to 56 days after the egg is fertilized. Often a women’s first pregnancy presentation occurs at about 28 days post fertilization (i.e. two weeks after a missed period) or later and this means that important opportunities to ensure a healthy foetus may have been missed. Women who consult their doctor prior to conception (i.e. have ‘preconception care’) have a significantly reduced incidence of babies with congenital abnormalities. (The overall incidence of congenital abnormalities in Australian babies is two to three percent.)

A much better approach to starting a new life is to have a pre-pregnancy check-up as soon as either partner has any thought about wishing to start a family. It should be done before contraception has ceased. From the GP’s point of view, it is worthwhile mentioning the benefits of such check ups to any woman who is in a long-term relationship.

Prior to starting a family, a woman will probably need to see a doctor only occasionally. This all changes with pregnancy and raising children and it is important to find a good family doctor. Hopefully the woman will already have a long-standing relationship with a GP. If not, it is useful to get to know a suitable like-minded GP well before becoming pregnant.

It is also worth mentioning that if a couple wish to have their baby delivered by a private obstetrician the woman will need to have health cover for at least 10 months before the due delivery date i.e. before she becomes pregnant. Private health insurance may also be a deciding factor in the choice of birthing centre available to the woman.

Becoming pregnant

Many couples have problems achieving a pregnancy, especially where one or both partners are older as is increasingly the case. (In 2007 about 22% of pregnancies occurred in women 35 years of age or older.) On average, 20 per cent of women trying to become pregnant will become pregnant each month. (This figure decreases with maternal age.) Investigating for sub-fertility is usually commenced once a couple has failed to conceive after 12 months of trying. However, it may be wise to consider earlier investigation if the couple is older. About one in six couples fail to conceive within 12 months of trying. (Half of these will conceive in the second year without medical intervention.)

Being significantly under or overweight is a common reason for difficulty in becoming pregnant, mainly due to problems with ovulation, and achieving a normal weight will often result in pregnancy occurring. The presence of polycystic ovarian syndrome is also a common cause. (It is also associated with obesity.) Obese women also have a higher miscarriage rate.

The current epidemic of pelvic inflammatory disease due to chlamydia is also likely to cause many cases of infertility now and in the future. The investigation of infertility is a complicated medical topic and is beyond the scope of this book.

With regard to fertility, smoking in women has a negative effect on ovulation and often results in an increased difficulty in becoming pregnant. (A woman who smokes has 'ovary-age' that is up to ten years older than would otherwise be the case.) Also, as well as being harmful to the prospective mother and to all in her household, maternal smoking is very dangerous to the unborn child.

With regard to the unborn child that the couple is hoping to conceive, the safest policy is for the prospective mother to avoid all types of medications / drugs at this time, especially consuming excessive amounts of alcohol / smoking.

The use of acupuncture, specific diets, and herbal therapies has not been shown to significantly influence the chance of becoming pregnant.

 

The importance of pregnancy and childbirth in bringing up healthy children

The graph below illustrates just how important foetal deveopment and childbith are in determining the health of children and why this section is so important. About 80% of the illness in the less than 1yr age group is due to infant and congenital conditions; mainly preterm, low birth weight, birth trauma and asphyxia, SIDS and cardiovascular abnormalities. (The good news is that illness due to these conditions has fallen 30% in the past 12 years due to better care.)

The first 1,000 days is the most important time in a child's development and goes from the time of conception till the age of 2 years.

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Pre-pregnancy heath issues and the pre-pregnancy consultation

There are numerous medical topics both partners will need to address in the pre-pregnancy consultation. They include the following.

Health problems associated with the physical and psychological trauma occuring with childbirth

Child birth is sometimes a traumatic time for women. Things do not go as expected; caesarians are needed, babies need time in intensive care etc etc. These issues left unresolved / untreated can cause significant upset and women often are reluctant or are not given adequate opportunity to address them. A good time to address them is the six week check up and making sure that a long appointment is made at this time is important. (Obviously some issues need to be addressed well before this time.) Advice regarding these issues is available from the Australian Birth Trauma Association at: www.birthtrauma.org.au

Resources for prospective and new parents

Beyond Blue's website provides a wealth of information for mothers and new parents about the many psycholosocial issues faced during pregnancy and afterchildbirth. A must read before becoming pregnant.

Beyond Blue: Pregnancy and New Parents https://healthyfamilies.beyondblue.org.au/pregnancy-and-new-parents

COPE (Centre of Perinatal Excellence) www.cope.org.au

Routine tests at the pre-pregnancy check up

Rubella titre: Women should have their rubella immunity checked and arrange to be vaccinated if necessary. (Rubella immunity checks can be unhelpful in some circumstances.)
Full blood count: It is important to ensure that anaemia is not a problem. (A full blood count can help identify low iron status and help in identifying the possibility of thalassaemia.)
Chickenpox (or varicella): All women who have not had or who are uncertain about whether they have had chicken pox in the past should be vaccinated.
Test for Hepatitis B infection: This is important as immunization at birth can prevent infection of the neonate with this serious infection. (There is no immunisation for Hepatitis C at present and transmission of this virus to the foetus / neonate is uncommon in any case.)
Whooping cough (pertussis): Whopping cough is a dangerous condition for the new born and the most likely route of transmission is from an infected parent. This risk can be minimised by non-immune parents and siblings being immunized prior to conception.
Tests for HIV where indicated (Some doctors feel that all women should be screened for HIV as appropriate treatment during the pregnancy and delivery can prevent transfer of this serious infection to the baby.)
Tests for possible genetic abnormalities e.g. Down syndrome, Thalassaemia. (This topic is discussed in detial below.)
Cervical cancer screening (Pap smear are being replaced by the HPV test in late 2017.)

Blood sugar test for women at increased risk of gestational diabetes

 

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Psychological preparation for pregnancy 

Most couples go to great lengths to prepare for a pregnancy including the following.

However, one aspect that is often left out is how the pregnancy and birth will affect the couple’s relationship. Couples face two particular challenges at this time:

  • coping with the demands of pregnancy, childbirth and the early months of parenthood; and
  • expanding their relationship to make room for their baby.

A ‘Pre - Parenthood Relationship Check – Up’ is worth considering to help with the adjustments you will need to make and your GP or childbirth educator will be able to advise you regarding available services in your area.

In the mean time, here are some steps you can take to strengthen your relationship with your partner.

1. Share your experience:
 Let each other know how you feel. Enjoy sharing the positive experiences; the happiness, the excitement, the sense of achievement. And be supportive when negatives such as anxieties and medical problems occur, as they often do.
2. Take control of your relationship: Hopefully this has been a change that you have planned or at least thought about as there are many significant pressures that occur on the relationship. As well as the pregnancy itself, there will be changes in work commitments, financial challenges, and altered relationships with other relatives, especially parents. Thus it is important to be clear about how you want your relationship to be, and to think about how the pregnancy and birth can improve and strengthen your relationship. It is a time for reflecting on your past ‘family life’ experiences; on what values and traditions you would like to maintain and which you would like to change.
3. Give yourself time
One of the unfortunate consequences of pregnancy and birth is that there is significantly less time for you as a couple. Try to make time for you without the baby. The new grandparents can be a great help here and it allows them to help without being overly intrusive in your household. An evening a month is certainly not unreasonable.
If you can't get help from your family, try trusted friends, especially if they have similar aged children so that you can reciprocate. 
Sexual relationships are always affected due to both physical and psychological changes. Lack of time, tiredness, changed body image perceptions etc all take their toll and it is quite common for sexual relations to temporarily cease for varying lengths of time. This does not mean there is less love; just that things have changed while adjustments are being made. Relationships will usually revert back to almost normal if patience and understanding are practiced.
4. Get help if you need it
Finally, if parenting is adversely affecting your relationship, think of getting some counseling early on before problems become entrenched. Remember that your difficulties will affect your children as well as yourselves. Often some simple advice from someone who understands your problems is all that is required. They will often have some simple solutions that you have not considered. Your GP will be able to help.

Recognising depression in pregnancy - Perinatal depression (PND)

Depression is a well-recognized problem after delivery with 10 to 15 per cent of new mothers becoming depressed. (Post-natal depression (PND) needs to be distinguished from a transient depression of mood that occurs in the first week after delivery in about 70 per cent of new mothers.) As with other types of depression, anxiety is commonly also present.

Recent research has shown that depression is at least as common during pregnancy (antenatal depression) and all people need to be aware of this problem so that they can help recognize symptoms in friends, relatives or themselves, especially if risk factors for depression are present. The incidence is lower in the first trimester, with an incidence of about 7%. The incidence in the second and third trimester is about 12%.

It is also important to realise that perinatal depression often does not resolvewith time after childbirth and that many women who suffer from the condition have long term problems with depression. Interestingly, recent research has found that most of the women who had problems with perinatal depresssion had a history of depressive symptoms often going back to their late teens.

Recognising perinatal depression (PND) is important as the condition is associated with numerous problems that be avoided with adequate treatment. These problems include the risk of developing chronic depression, harm to the baby / other children and long term affects on the womans relationships with her partner, family and friends.

The risk factors for PND include:

  • a past history of significant depression / anxiety. This is a very important factor, especialy if the mental illnessstarted relatively early in life; in the late teens. Women with a past history of depressive symtoms have a 50 per cent chance of developing perinatal depression. (Only about 6% of women with no past history of mental health problems develops perinatal depression whereas the rate is about 33% in women with a past history.) A tendency to worry / be pessimmistic is also an important indicator.
  • previous perinatal depression
  • lack of practical social support, especially if the woman has other childen
  • lack of emotional support
  • poor quality relationship with partner (and thus poor support) / dysfunctional interpersonal skills
  • ambivalence about being pregnancy
  • teenage pregnancy
  • current major stresses or losses
  • a history of domestic violence
  • a history of alcohol abuse / illicit drug use
  • a history of childhood abuse
  • problems with the pregnancy / delivery / baby, including premature delivery.

Prevention of PND relies on maximising family support and providing time for relaxation, especially if this is not the first child. Sleep deprivation and over–working need to be avoided as well. Fathers and grandparents can be a great help here.

It is thought that only about 50 per cent of women with PND are diagnosed and treated. For this reason, programs aimed at identifying women who are at risk of or who have post-partum depression are now commonly used introduced in Australia and should be part of both every woman's antenatal and postnatal care.

Further information about PND can be found in the Beyond Blue web site.

Beyond Blue: Pregnancy and New Parents https://healthyfamilies.beyondblue.org.au/pregnancy-and-new-parents

Any woman who has thoughts of suicide or harming a baby or other children needs urgent (same day) specialist mental health assessment.

 

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Screening / testing for foetal genetic abnormalities

Genetic abnormalities are a relatively common occurrence, with the vast majority being present at the time of conception. The incidence increases with maternal age but not paternal age. This is because all the ova are present within the ovary before the mother is born and are thus subject to mutating influences throughout the mother's life. Sperm, on the other hand, are continually being formed thoughout the father's life and thus are exposed to mutating influences for a very short period. The table below shows the variation in the incidence of chromosomal abnormalities in newborn babies with increasing maternal age. (The table actually underestimates the rate as most affected severely affected foetuses spontaneously abort in the first month after conception.)

Most commonly there is no past family history of genetic abnormality when such abnormalities occur. However there are some inherited conditions, with the most common / significant ones being mentioned below. (Some of these conditions can skip generations.)

Testing for genetic abnormalities can be either;

It is important that parents discuss the implications of testing fully with their medical practitioner before having tests done so that they can decide whether they really want to have the test done and what they will do if an abnormality is found.

 

Risk of any chromosomal (genetic) abnormality

Maternal age

Risk

20

1 in 526

25

1 in 476

30

1 in 384

35

1 in 204

40

1 in 65

45

1 in 20

49

1 in 7

 

Testing for Down syndrome and other chromosomal abnormalities

One in every 700 live births in Australia has Down syndrome and the proportion of cases will increase as the age of mothers increases in our society (see table 32). Most cases of Down syndrome (over 97 per cent) are due to the presence of an additional chromosome 21 (Classical Trisomy 21). This occurs as a sporadic event and is not inherited (i.e. it does not affect other family members). The other cause is a translocation abnormality of chromosome 21. This can run in families and parents who have a Down Syndrome foetus need to be checked for this abnormality so that other family members can be advised if they are at increased risk of having a Down syndrome child. This increased risk can be as high as 10 per cent.

Risk of Down Syndrome occuring

Maternal

age

Risk at

12 weeks

gestation

Risk at

20 weeks

gestation*

20

1 in 1068

1 in 1295

25

1 in 946

1 in 1147

30

1 in 626

1 in 759

32

1 in 461

1 in 559

34

1 in 312

1 in 378

36

1 in 196

1 in 238

38

1 in 117

1 in 142

40

1 in 68

1 in 82

42

1 in 38

1 in 46

44

1 in 21

1 in 26

*The risk is lower at 20 weeks because some women with a Down Syndrome foetus will miscarry between 12 and 20 weeks.

Decisions about testing for Down syndrome are best made prior to becoming pregnant. There are two main types of tests, screening and diagnostic. (It is worth mentioning that many of the tests mentioned below are not available in some country areas and country women wishing such testing may need to travel to the city. Also, these investigations require considerable techical skill and it is very important that women make sure the medical personel performing any test / procedure is well qualified to do so. This includes doctors, radiographers and pathology technicians. Ask your GP.)

Non-Invasive Prenatal Screening Testing

Foetal DNA is present in the mother's blood from early on in the pregnancy. (It originates from dead placental cells that are fetal in origin. The death of some of these cells is a normal process.) Using a blood sample taken from the mother, detected foetal DNA material can be tested for numerous genetic abnormalities that can occur in the foetus and that are not present in the cells of the mother or father. This test is mainly used to determine the likelihood of Down Syndrome being present but it can also detect the presence of other abnormalities. At present the other abnormalities being commonly tested for includes Edwards syndrome (trisomy 18), Patau syndrome (trisomy 13), Turner syndrome (XO), Kleinfelters syndrome (XXY) and Triple X (XXX).

Testing is a complicated process that involves identifying and replicating the chromosomes where these genetic abnormailies occur.

As only some of the foetal chomosomes are replicated and tested, this test does not provide as much genetic information as invasive tests, where all the foetal chromosomal material can be examined. For this reason it will miss some types of chromosomal abnormalities (about 25%). The fact that the test does miss some types of chromosomal abnormalities means that all pregnancies at high risk of chromosomal abnormality, either due to maternal age or positive testing, should really have an invasive test in preference to NIPT.

It is important to realise that part of this process involves finding out the sex of the foetus.

Usually the maternal genome is used as the reference genome so this type of testing should not be used if the pregnancy has been conceived with a donor egg.

This testing is very accurate, diagnosing about 99% of cases of Down syndrome with a false positive rate of only about 0.2%. This is much better than conventional screening testing which only diagnoses about 90% and has a false positive rate of 5%. As well as improving accuracy, this improved detection rate greatly reduces the number of invasive tests that are done on women who do not have afoetus with Down syndrome; and about 1% of these invasive tests results in a misscarriage. The test is usually done from 9 to 13 weeks.

As there is a small number of false positive results, women who have a positive result need to have a diagnostic test to confirm the presence a Down syndrome (or another genetic abnormality).

To give an accurate result the maternal blood must contain at least 4% foetal DNA in the blood sample and about 3% to 5% of samples do not provide this amount. Retesting provides an adequate sample in about half of these cases. Failed results are more common in women weighing over 120kg.

It is important that women who choose to have this test also have an ultrasound at 11 weeks as this can detect other abnormalities such as neural tube defects and other non-genetic abnormalities.

At present the test is not covered by medicare. The cost is a few hundred dollars (as at Feb 2018).

Combined first trimester screening (cFTS) and Second trimester screening tests

These tests do not diagnose Down syndrome; rather, they categorise women into low risk (more than one in 300) or high risk (less than one in 300) of having a Down syndrome baby. Women found to be at high risk are generally advised to have further investigation with a diagnostic test; either chorionic villus sampling or amniocentesis. However, in the end it is up to the individual woman to decide whether she would like to proceed to diagnostic testing. For example, a young woman aged 25 may wish to proceed even though she had a risk level below 1 in 300 (say 1 in 400) whereas a woman aged 40 who has had great difficulty conceiving may choose not to go ahead with a risk level of 1 in 200.

Screening tests are available (and should be offered) to all pregnant women and are especially useful for women who are either at low risk of having a Down syndrome child (i.e. 'normal' young mothers) but would like some extra reassurance without having to undergo an invasive procedure or who do are unhappy about the small risk of miscarriage with diagnostic tests. (See below.)

Important: First trimeter screening that includes an ultrasound (see below) provides much important information about the pregnancy in addition to that relating to genetic abnormalities such as Down Syndrome. Thus all women should be encouraged to have first trimeter screening.

Generally, first trimester screening detects about 90% of Down syndrome cases (i.e. it misses 10%) and about 2.5% of women tested are categorised as high risk. There is a false positive rate of about 5%. Women over the age of 35 years are all deemed to be at high risk due to their age and should therefore all automatically be offered a diagnostic test.

There are two disadvantages of these screening tests.

There are two types of screening test available for indicating the risk of Down syndrome; first trimester and second trimester.

Combined first trimester screening (cFTS): The combined Nuchal translucency ultrasound and first trimester biochemical screen
Screening in the first trimester that includes the use of ultrasound and biochemical (blood) tests is the most effective method of screening for Down syndrome and they also provide a wealth of other very important information. (They will also pick up most cases of Trisomy 18, another type of genetic abnormality, and neural tube defects). Also, the earlier diagnosis of foetal abnormalities that first trimester screening provides makes terminating the pregnancy easier should that course of action be chosen.

Thus, cFTS should be recommended in all pregnancies. Roughly about 5% of first semester screening produces a positive or ‘high risk’ result for Down Syndrome.

The blood test, which measues two chemicals (fbhCG and PAPP-A), can be done from week 9 to week 13 and the ultrasound test from week 11 to 13.) The ultrasound test checks the fluid content of the foetal neck skin folds and a thickness greater than normal indicates an increased risk of Down syndrome. (It can also be abnormal in foetuses with heart and kidney problems.) The test must be performed by a specially trained (and accredited) ultrasonographer as the accuracy of ultrasound screening depends on the comptence of the person doing the test. In abnormal tests, the size of the abnormally thick neck skin fold is important in determining the likelihood of an abnormality and what should be done. A fold size 2.5mm or greater indicates an increased total risk of foetal abnormality and referral to a specialist foetal medicine unit is warranted for further specialised testing, including detailed ultrasound testing. An abnormal level that is less than 3mm is referred on for one of the diagnostic tests mentioned below (i.e. chromosome testing). If the diagnostic test is normal, the risk of abnormality is low and further investigation is not warranted. Unfortunately and understandably, such results do raise anxiety levels amongst prospective parents through the remainder of the pregnancy.

One uncommonly occurring disadvantage of first trimester screening is that very occasionally a Down syndrome pregnancy that parents choose to terminate would have spontaneously aborted by 18 weeks. In this situation the patents would not have had to make the choice. On the other hand, a major upside of early screening is that termination of the pregnancy if required is easier as it can be done surgically. Once the pregnacy is as advanced as 18 to 20 weeks, termination requires labour to be induced and the foetus to be delivered.

First trimester screening in twins: For identical twins, there is no diference in the effectiveness of first trimester screening. For non-identical twins, the diagnosis rate of first semester screening for Downs syndrome is significantly lower; about 80%.

Second trimester screening (using the Triple or Quadrupal Screening tests):
Second trimester screening is inferior to first trimester screening and the timing makes termination more difficult. Thus, it should really only be used when the woman presents too late for first trimester screening or in more remote areas where suitable ultrasound facilities are not available.

All the tests are blood tests that are taken from the mother early in the second trimester; generally at 15 to 17 weeks but they can be done up to week 20. (The triple test tests for alpha-fetoprotein, unconjugated oestriol, and beta-HCG, while the more commonly done quadruple test measures inhibin-A in addition to the 'triple-test' compounds.) Again about five per cent of pregnancies are classified as being at high risk by this set of tests. Done alone, these tests miss about 40 per cent of foetuses with Down syndrome but they are better at detecting neural tube defects. (The fact that about 30 to 40 per cent of Down syndrome foetuses alive at 12 weeks will have spontaneously miscarried by 40 weeks means that, as this test is done later than the first trimester ultrasound tests, it is hard to compare their respective ‘miss rates’.) The quadruple test misses fewer cases than the triple test. It is important to be aware that the detection of Down syndrome in women under the age of 30 years using second trimester screening alone is generally poor. (Thus the tests provide no guarantee of a genetically normal baby.)

Accurate ultrasound dating of the pregnancy improves the diagnosis rate and reduces the false positive rate associated with second trimester screening.

As mentioned above, the fact that second trimester screening is done later means that if a termination of pregnancy is required it needs to be done by inducing labour and the vaginal delivery of the unviable foetus.

The combination of first trimester screening (ultrasound and blood tests) and second trimester screening does not offer any significant benefit over first trimester screening alone (and does in fact increase the false positive rate).

If either first or second trimester screening is abnormal (i.e. indicates a high risk of foetal abnormality), the woman is offered diagnostic chromosomal testing (usually amniocentesis) and detailed ultrasound testing to help rule out foetal abnormalities.

 

Invasive diagnostic tests using a sample of amniotic fluid (amniocentesis) or of the placenta (chorionic villus sampling (CVS))

Traditional diagnostic tests are invasive and involve taking either a sample of amniotic fluid (amniocentesis) or a sample of the placenta (chorionic villus sampling (CVS), which is done under ultrasound guidance. The chromosomes of the foetal cells obtained are then examined for numerous genetic abnormalities, including Down sydrome. Therefore, unlike screening tests, diagnostic tests can actually diagnose genetic conditions very accurately. However, no test is perfect and a normal result does not diagnose all Down syndrome cases and misses some very rare conditions that are not identifiable with chromosome testing. (In all, diagnostic genetic screening can be expected to diagnose about 99.4% of all chromosomal abnormalities present in the foetuses of the prospective mothers who undergo CVS or amniocentesis and they diagnose over 99% of all the Down syndrome cases carried by the foetuses of these women.)

CVS can be done earlier (at 11 to 13 weeks) than amniocentesis (usually done at 15  to 18 weeks). This means that terminations following CVS can be done surgically (by curette), whereas terminations following amniocentesis need to be done via an induction of labour, which is significantly more traumatic for the mother.

As stated above, they are both associated with an increased risk of miscarriage.

Amniocentesis carries a miscarriage rate in addition to the 'normal incidence' of about 1 in 100 to less than 1 in 1000 and CVS carries an extra miscarriage rate of about 1 in 100 to 1 in 400. The rate for CVS is improving. (The miscarriage rate is less for transabdominal CVS compared to transcervical CVS and most centres now do the procedure transabdominally. The CVS misscarriage figures quoted are for transabdominal CVS.) The variation in miscarriage rates reflects the variation in expertise of the medical personel involved in performing the procedures.

Invasive diagnostc tests are generally available only to women who are at high risk because of their age (over 35 years is the usual criteria) or because they have a ‘high risk’ screening test result. Invasive diagnostic tests are not offered as a first line screening investigation to all women because they do carry a slight risk of miscarriage. While this is usually very low, it would be likely to increase significantly if the tests were offered to all women as there are not enough suitably trained doctors to perform the larger number of procedures that this would involve. (There are also not enough suitably qualified cytogenetic pathology services available to do the required testing.)

It is important to realise that non-invasive first trimester screening tests provide much more information regarding the pregnancy that just information relating to genetic abnormalities. Thus, they always need to be done, irrespective of whether an invasive test is done.

Pre-implantation genetic testing

Where a high risk of an inherited genetic condition has been confirmed by family history or genetic testing or is suspected due to repeated misscarriages, the foetus can be tested before implanation in the uterus to exclude the presentce of the condition. This involves using IVF techniques to produce the foetus and the examination of foetal cells for abnormalities prior to implantation in the uterus. Thisensures that only non-affected embyos are used.

A protocol for testing for chromosomal abnormalities

At present (2016), doctors commonly recommend the following protocol for Down syndrome testing.

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Prenatal testing

 

Screening tests for all pregnant women

 

Test

Timing of test

Information given

Combined first trimester screening (cFTS)

(blood tests and ultrasound)

 

9 to 13 weeks (week 11 is best) for blood tests (two compounds: PAPP-A & free beta-HCG)

This is best practice first trimester screening and is recomended for all pregnancies. It detects about 91% of Down syndrome cases with a false positive rate of about 5%.

Confirms due date.

Identifies twins / miscarriage.

Helps detect other severe foetal abnormalities.

11 to 14 weeks for nuchal translucency ultrasound

Nuchal translucency alone

 

11.5 to 14 weeks

Helps detect Down syndrome but is less accurate than combined first trimester screening.

Confirms due date

Identifies twins / miscarriage

Second trimester maternal screen

(Quadruple test)

Beta-HCG, alpha-fetoprotein, inhibin A, oestriol

15 to 17 weeks

Detects 70 to 75% of Down syndrome foetuses.

Gives risk result for neural tube defects / Edward syndrome

Second trimester ultrasound alone

18 to 20 weeks

Detects major physical foetal abnormalities, which occur in about 2% of births, and is especially good at detecting neural tube defects e.g. spina bifida.

Measures foetal growth.

Locates position of placenta.

Diagnostic tests for women determined to be at increased risk of foetal  genetic (chromosomal) abnormalities

 

Test

Timing of test

Information given

Chorionic villous biopsy

10 to 13 weeks

Diagnoses all major chromosomal abnormalities with great accuracy including about 99% of foetuses with Down Syndrome.

Amniocentesis

15 to 19 weeks

Diagnoses all major chromosomal abnormalities with great accuracy including about 99% of foetuses with Down Syndrome.

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Testing for inherited conditions

If you have a family history of a genetic disease, specific tests may be required. It is important to discuss any family genetic disorders with your general practitioner before becoming pregnant. (Common inherited conditions include haemochromatosis, cystic fibrosis, thalassaemia, neurofibromatosis, muscular dystrophy, non-syndromic hearing loss, fragile X syndrome (which causes mental retardation).)

While some inherited genetic abnormalities are known to the family, in many cases they are not. Indications that an unknown genetic genetc abnormality may exist in a family include the following.

The presence of any of the above in the family of either partner may indicate that a inherited genetic problem exists and should be also mentioned to treating doctors.

Also, some genetic abnormalities have a significantly higher incidence in certain ethnic groups (see table below). Members of these groups need to discuss with their doctor potential problems relating to diseases in their racial group and carefully research any family history of the disease.

As stated above, genetic testing involves providing a sample of saliva from both partners. The DNA in the cells contained in the saliva is examined for specific abnormalities and results are available in about 6 weeks. It is not covered by medicare and costs around $700 to $1,000 per person.

Routine genetic testing for couples not at increased risk

There are over 7,000 severe recessive childhood genetic disorders and, on average, all people carry at least three of these recessive genetic abnormalities. Most of these are very rare and not tested for. About 3% of babies are born with some sort of birth defect / condition with most being a mild problem and it will never be possible to prevent most of these.

Having said this, it is becoming more common for couples who are not at high risk of having a baby with an inherited genetic condion to be tested for some more common severe inherited conditions, especially cystic fibrosis, fragile-X syndrome and spinal muscular atrophy. Currently this is not a topic that is commonly brought up by doctors so it is up to patients to ask if they are thinking of having a baby would like to be tested.

A recent study by the Murdoch Children's Research Institute (2017) of 12,000 individuals found that one in every 240 couples was at high risk of having a child with spinal muscular atrophy, cystic fibrosis or fragile X syndrome. This means that about one in 1,000 babires of women who were carriers of one of these conditions would be affected by one of the conditions. This incidence is significant enough for the researchers to recommend routine genetic testing for all couples for these conditions prior to pregnancy.

Couples wishing to undertake such testing need to discuss the ramifications with a genetics specilist before doing so as the consequences of a positive test are significant, both for the couple being tested and their immediate family. This obviously needs to be done BEFORE the pregnacy occurs. The resources available for such counselling are limited and thus many people will need to have discussions with their GP instead. In either case, patients should become well informed about this topic before having such discussions.

Some doctors offer testing for many other genetic abnormalities as well and deciding what to do about a positive test can be difficult and requires expert advice.

The genetic abnormalities mentioned below can be avoided by identifying couples at risk through genetic testing and using either

  • IVF with pre-implantation genetic diagnosis (i.e. chooosing an unaffected foetus for IVF implantation) or
  • natural conception, prenatal diagnosis and termination of the pregnancy if the foetus is affected.

Finally, it is important to understand that, while genetic screening is very accurate, it is not perfect and a small number of cases will be missed by screening.

A. Testing for beta-thalassaemia status

Beta-thalassaemia is the most common human gene disorder in the world. It is estimated that 1 in 100 Australians carry the beta-thalassaemia trait and it is more common in people of Italian, Greek, Turkish, Cypriot, Lebanese, Maltese or South-east Asian descent (up to 10 per cent). Carriers are relatively unaffected but those with the disease develop significant anaemia and require blood transfusions throughout life.

If you belong to one of these ethnic groups, you can be tested for this disease. If your test is positive, then your partner should be tested for the abnormality as this disease is only a significant problem if the gene is passed to the child from both parents. Tests that can help show whether a person carries the thalassaemia trait are a full blood count, haemoglobin electrophoresis and a serum ferritin. (Diagnostic tests do not involve looking at genetic material.)

If both parents are affected, then the couple has the option of having the foetus tested for the disease and a termination of the pregnancy done should the foetus be affected. Such testing requires that the parents’ genetic material (DNA) is studied first and this takes several weeks. Because of the time involved in the above process, it is vital that it is done prior to the woman becoming pregnant. If it is not undertaken until after the pregnancy has occurred, extra stress is placed on the couple to get everything done quickly and important decisions may need to be rushed. Also, the options available for termination, should it be wished, may be restricted by the more advanced stage of the pregnancy. Planning ahead is best!!

B. Alpha-thalassaemia

There are four separate genes for alpha-thalassaemia. The condition is not significant unless at least two of these genes are affected. However, this occurs quite commonly in the Asian community with an incidence of about 1 in 20. As in beta-thalassaemia, the genes need to be passed onto the foetus by both parents for the disease to occur and in alpha-thalassaemia significant illness does not occur unless both parents have at least two of the four alpha-thalassaemia genes affected.

C. Fragile X syndrome

This is the most common single gene cause of mental retardation and also causes other major mental illnesses such as major anxiety, ADHD, and autism spectrum disorders. The disabilities are moderate to severe in most cases. Its incidence in Australia is about one in 10,000. It is an autosomal dominant condition and the gene can be passed on by either parent. (The carrier rate of the genetic abnormality is about one in 250.) However, the gene only causes problems when the mother passes on the gene and a mother who is a carrier has a 50% chance of passing the gene to the foetus. However, only about 50% of foetuses who receive the gene from their mother develop the condition. Whether they do or not depends on the size of the gene expansion, a feature which can be determiined by genetic testing of the mother. (The risk can vary from 5% to 100% depending on the length of the gene expansion. The shorter the expansion, the less is the risk.)

Genetic screening of women for the disease should be done prior to pregnancy as the condition can be prevented

Overall the screening for this disease should be considered in any person who has an undiagnosed intellectual disability, individuals with a family history of undiagnosed mental retardation and women with a history of ovarian failure. (Female carriers of this condition have a 20 times normal incidence of ovarian failure.)

Additionally, as most people who develop the disease do not have a family history of the condition, there is a good case for screening all women prior to them becoming pregnant. As with all genetic testing, this should be offered only after the couple have had genetic counselling so that they understand the implications of a positive test. Women who are shown to be carriers can be offered IVF using an ovum that has been shown to contain the gene. (Only half the mother's ova will carry the gene.)

Genetic testing for Fragile X syndrome is not routinely offered at present to pregnant women. However, many pregnant women would opt to have the test done if given the choice. A mother who is a carrier has about a 25% chance of the foetus being affected.

Carriers of fragile X may also have problems

Carriers of fragile X are at increases risk of fragile-X associated tremor/ataxia syndrome and, in the case of female carriers, premature ovarian failure and infertility. Thus, testing can have ramifications for the health of the person being tested and members of their family such as brothers and sisters.

 

D. Cystic fibrosis

Cystic fibrosis is a recessively inherited condition that is relatively common in the anglo-celtic community; about 1 in 2,500 live births. The carrier rate is about 1 in 25. Those with a family history of this disease need to discuss it with their GP. Prenatal testing to diagnose an affected child early on in the pregnancy is offered to couples where either partner is a known carrier or where the couple already has an affected child. This testing will diagnose the vast majority of cases but not all of them as there are over 1,000 different genetic abnormalities that can cause cystic fibrosis and tests are only available for the common ones.

While such testing is of great benefit to individual families, it does unfortunately not reduce the community incidence of the disease to any great extent as the vast majority of cases occur in the children of couples where there is no history of either carrier status in the parents or the disease within the family. For this reason it has been suggested that all couples be offered screening tests to see if they are carriers either prior to pregnancy or in the first stages of pregnancy.

Such a program is already operating in Edinburgh, Scotland, and it has led to a halving of the number of cases of cystic fibrosis through early diagnosis in the pregnancy and subsequent termination of the pregnancy. While there is no community based testing program operating in Australia, couples who would like to be tested can do so by contacting Sydney Genetics in Sydney (Ph 9229 6495).

Testing is easily done by rubbing a swab over the cheek and this can then be sent by post to be tested.

Options for people who have been found to be carriers of cystic fibrosis (or other genetic disorders)

  • Become pregnant and have no testing
  • Become pregnant and have their unborn child tested in utero, usually at about 11 weeks by chorionic villous sampling, for the disease. The parents then have the option of having a foetus that is found to be affected terminated. (Obviously there is very little point in having this test done if termination is not an option.)
  • Have the child by in vitro fertilization (IVF). This enables the resultant embryo to be tested for the disease prior to implantation in the uterus. The obvious advantage here is that a termination of the pregnancy is not required if the embryo is found to be affected. However, it is not as accurate, has all the inconveniences associated with IVF and is costly. (Also, because it is not as accurate, in-utero testing is done as an additional safe-guard to help minimize the risk of missed cases.)
  • If testing was done prior to conception, then using donor sperm or egg or embryo to replace the egg or sperm or embryo of the carrier parent(s) is an option. This will involve IVF where a donor embryo or egg is used. Obviously the donor(s) need to be tested for the condition.
  • Choose not to have children.

E. Spinal Muscular Atrophy

This is another genetic condition that is fatal. It can be screened for prior to pregnancy and is thought to be worthwhile offering to couples by some medica authorities. It is not usually offered to couples at present. It is a recessive genetic abnormality which means both parents need to have the abnormality for a foetus to have a chance of being ffected and when they do, there is a 25% chance that baby they have will be affected. The disease can be prevented by using IVF techniques using sperm / ova from the parents that do not have the genetic abnormality. About one in 40 people have the genetic abnormality (i.e. it is quite common) and the incidence of the condition is about one in 10,000 births; about 630 cases per year in Australia. Most couples who have a baby with this condition have no family history of the disease.

Genetic conditions of ethnic groups

Disease

Ethnic group

Carrier frequency

Test for carrier status

Beta-thalassaemia*

Italian, Greek, Lebanese, Indonesian

1 in 7 to

1 in 20

Full blood count,

Haemoglobin electrophoresis

Alpha-thalassaemia*

South-East Asian,

Chinese

1 in 10

As above

Cystic fibrosis*

Anglo-Scottish,

Ashkenasi Jews,

1 in 20 to 25

Genetic testing

Tay-Sachs disease*

(a metabolic disease affecting the nervous system)

 

Ashkenasi Jews, (also French Canadians to a lesser extent)

1 in 20 to 30

Serum hexosaminadase (This test is unreliable in pregnancy)

Sickle cell disease*

(causes anaemia)

African, African American, Mediterranean and Middle-eastern

1 in 30 (Africans)

1 in 650 (African Americans)

Full blood count,

Haemoglobin electrophoresis

*All these conditions are recessively inherited and thus require both parents to be carriers and transmit the affected gene to the foetus for the foetus to be significantly affected by the disease. The second parent thus needs to be tested if one parent is found to be a carrier. However, having either parent as a carrier does mean that the child may also be a carrier of the disease.

Source: Royal Australian College of General Practitioners, CHECK PROGRAM - Genetics ,  March 2001 .          

Copyright permission to reproduce must be sought from the publisher, The Royal Australian College of General Practitioners. 

 

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Infectious diseases during pregnancy

 A. Infectious diseases that can be prevented by immunization

1. Rubella

Rubella contracted in pregnancy can cause serious foetal abnormalities, including growth retardation, cataracts, hearing loss and heart problems. These abnormalities are more likely to occur when the disease occurs early in the pregnancy as there is a greater risk of the disease being transmitted to the foetus.

This risk decreases quickly as the pregnancy progresses, with the risk of foetal transmission being about 20 per cent at 12 weeks and less than one per cent after 20 weeks.

Up to ten per cent of all pregnant women are not immune to rubella. (This figure is higher in some immigrant groups where immunisation levels are low). Thus, rubella titres need to be checked in all women and immunization given if needed. Remember that pregnancy is a contraindication to rubella vaccination as there is a slight potential risk that the vaccine will affect foetus. Should a woman accidentally be immunised while pregnant, she should contact her doctor immediately. (Most babies born to women who are accidentally immunised when pregnant are born without any normally.) Women should also avoid becoming pregnant in the two months following rubella vaccination.

To help prevent this problem, it is recommended that all adolescent females and males be given the MMR vaccination. (This gives additional protection against mumps and measles as well.)

2. Chickenpox (or varicella):

Women who have not been vaccinated against chicken pox should have their immunity checked before becoming pregnant. Those found not to have immunity (about 10 per cent of unvaccinated people in Australia) should be offered vaccination before they become pregnant. The vaccination consists of two injections given at least one to two months apart. As the vaccination involves giving an attenuated live varicella virus, pregnancy should be avoided during vaccination and for a month afterwards to avoid transmission of the attenuated virus to the foetus. (Impaired immunity is also a contraindication to having the vaccine.)

About five per cent of women who state they have had chicken pox are not immune. For this reason, it has been suggested by some doctors that all women should be checked for immunity to chicken pox. This is not accepted practice at present because very high levels of immunity in the adult community make it unlikely that these women will contract the disease.

If varicella infection occurs in the first 20 weeks of the pregnancy, there is a two to three per cent risk of foetal abnormalities developing.  If a non-immune pregnant woman comes into contact with a person with chicken pox, she can be offered zoster immune globulin to reduce her risk of both maternal and foetal infection. This usually has to given within 48 hours of exposure to be effective. (Chicken pox can also be dangerous for the pregnant woman as she can develop a potentially life threatening lung infection.)

3. Whooping cough (pertussis):

Whopping cough is a dangerous condition for the newborn and the most likely route of transmission is from an infected parent. This risk can be minimised by non-immune parents and siblings being immunized prior to conception. This will help prevent the likelihood of transmission within the family and the new-born baby will gain some protection via maternal antibodies he or she received via the placenta.

4. Influenza

Influenza, like whooping cough, is a dangerous condition in newborn infants. If the baby is likely to be born in the flu season (i.e. the time that influenza is most likely to be a problem), the mother should consider having an influenza vaccination to provide the newborn infant with some protection against this condition.

5. Hepatitis B infection:

All children are immunized at birth in Australia against Hepatitis B to prevent infection of the neonate with this serious infection. (To prevent spread of this infection from a mother carrying the disease to her new born baby, vaccination of the baby should optimally occur within 24 hours of birth and must occur within 7 days of birth.) Non-immune women should be offered immunization. (There is no similar treatment for Hepatitis C at present and transmission of this virus to the foetus / neonate is uncommon in any case, occurring in about four per cent of cases.)

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B. Infectious diseases that can NOT be prevented by immunization

1. Toxoplasmosis:

Toxoplasmosis is an infection that generally causes no symptoms when contracted by healthy people after birth. However, if the mother becomes infected for the first time during pregnancy, it can be transmitted from the mother to the foetus. About 25 to 35 per cent of women of child-rearing age in Australia have immunity to toxoplasmosis from prior exposure and thus are not at risk of contracting the disease during pregnancy. In Australia foetal infection is very uncommon but in other countries the rate of foetal infection is significant. For example, the rate in France is about 1 to 3 per 1000 live births. The primary host is the domestic cat.

Infected babies are well at birth but later can develop various abnormalities including eye problems, epilepsy and mental retardation. Infection mostly occurs by oral transmission from undercooked meats or raw unwashed vegetables or from contact with infected soil. It can occur from cats’ litter boxes but rarely from direct cat contact. Prevention is best achieved by washing hands well before eating any food, ensuring that all meats are well cooked and that all fruits and vegetables are thoroughly washed before being consumed, and avoiding handling cat litter boxes. Diagnosis is usually made by blood tests for antibodies the body makes to the organism. The IgM test is used to detect recent infection and unfortunately this test is not very reliable with false positive tests occurring at least as often as true positives, leading to unnecessary further investigation and sometimes termination of the regnancy. Screening for past immunity which includes doing an IgM test is thus usually not recommended. As there is no vaccination available, minimizing the risk of exposure is the only option to reduce the risk of foetal exposure to the disease. (See boxed section at end of this section.)

2. Cytomegalovirus (CMV)

CMV infection is a common viral disease in the community and by early adulthood at least 50% of the population have become infected. Infection mostly occurs through contact with young children (via saliva and faeces) but also occurs through long-term contact with an infected adult. (Sexual transmission also occurs.) Most infections are relatively minor and cause nothing more than a ‘cold-like’ illness. This means few people are tested for CMV and thus most are unaware they have the disease. Infection is life-long but most people remain without symptoms following the initial illness. Occasionally reactivation can occur; mainly in people whose immune systems are compromised in some way.

CMV is the most common cause foetal abnormality due to cogenital infection and can cause both deafness and mental retardation. Primary infection of the mother during pregnancy occurs in about 1 in 300 pregnancies and the virus is transmitted to the foetus in about 40 per cent of these cases. Infection of the foetus can also occur during a reactivation of a past infection, although such foetal infections are relatively uncommon in well women.

There is considerable individual variation regarding the effect of the virus on an infected foetus. Most infected babies show no ill effects but a minority do develop significant illness; mainly growth problems, deafness and mental retardation. This is more likely to be a problem if CMV is contracted by the foetus early on in the pregnancy when body organs are forming.

Testing for CMV in pregnant women is complex and involves testing for antibodies the body produces against the virus. The reliability of these tests is good when the woman has had recent typical CMV-like symptoms but false positive tests are a problem in women who have not had symptoms of the disease. For this reason testing is usually done only in women who have had a recent CMV-like illness. The production of IgM antibodies is the body’s initial response following infection and their presence usually indicates a recent infection. IgM antibodies usually disappear a few weeks after infection. Long lasting IgG antibodies are produced gradually after an initial infection and a significant rise in IgG antibodies also indicates a recent infection. This is generally a more reliable indicator of recent infection as false positives are more common with testing IgM antibodies. (Demonstrating a rise in IgG obviously requires two tests done a few weeks apart.) Reliable diagnosis of a recent infection requires a blood test soon (within a few weeks) after the infection occurs. The presence of a significant level IgG antibodies and few IgM antibodies on the first blood test, if done soon after infection, usually indicates a past infection.

Obviously any testing is of little value to women who would not be prepared to have the pregnancy terminated as it may cause unnecessary worry.

Unfortunately there is no preventive vaccine for the disease and the place of antiviral drug therapy in pregnant women is complex due to side effects and the fact that the babies of many infected women will develop no significant disability. (And most women are, in any case, unaware that they have been infected and thus treatment is not even an issue.)

Prevention is thus the best option for most women. It relies on trying to avoid contact with the disease in women who have an increased risk of exposure. This group mainly includes child-care workers (young children are a common source of CMV infection) and they should be particularly careful about washing their hands after changing nappies and avoiding contact with baby saliva. It may also be worth checking their immune status prior to conception and perhaps rechecking this during the initial stages of the pregnancy. Hand washing, particularly during food preparation and eating, is vital in the home as well (especially if there are yopung children).

3. Listeria infection:

Listeria is a bacterial infection that can cause still births, premature labour, and significant illness in the newborn. Such problems are fortunately very uncommon. Pregnant women who contract the disease, usually from food, often only have minor non-specific viral like symptoms and thus, like toxoplasmosis, it is difficult to diagnose early. Prevention is best achieved by avoiding contact with the bacteria. The list of foods that can carry the bacteria is unfortunately fairly long and keeping to a diet that avoids these foods can be difficult. Thus, the fact that this is an uncommon diseease needs to be borne in mind. The following measures can help reduce the likelihood of contact with Listeria.

  • Thoroughly cooking raw food from animal sources.
  • Avoiding unpasturised milk and milk products, including thick shakes, soft serve icecream, cold cream products not made at home, and soft cheeses, such as brie, camembert, fetta, ricotta and blue-veined;  
  • Avoiding delicatessen meat products, commercialy made pate, and takeaway foods containing meat (or cooking them again at home).
  • Washing raw vegetables well before consumption. Salads prepared away from home should be avoided also.
  • Washing hands and implements after handling uncooked meats and raw vegetables (including cutting boards);
  • Separating prepared food from uncooked meats and unwashed vegetables (including in the fridge).

4. Parvovirus. (Erythema infectosum / fifth disease / slapped face disease):

This is usually a disease of children which occurs in epidemics that often last several years. Pregnant women are usually infected via their school aged children or when in contact with children via their work and roughly 25 per cent of adult staff at schools will show evidence of contracting the disease when epidemics are occurring. During such outbreaks it may be worthwhile excluding susceptible pregnant women from the classrooms.

Parvovirus presents in children with a rash, especially on the face, fever and joint pains, while in adult women there are often no symptoms. (The most common adult symptom is pain in the peripheral joints; that is the hands and feet.) In the foetus it is mainly a problem in the first 20 weeks of a pregnancy, when it can occasionally cause a serious anaemia.

Only about 40 per cent of women are susceptible, the rest being immune from previous exposure to the disease. (Immunity can be tested in pregnant women who come in contact with the disease and reassurance given if the test is positive.) Of those susceptible, only about half will get the disease and in only half of these will the foetus become infected.

While prevention of the disease is difficult, it needs to be emphasised that even when the foetus is infected, the disease is usually benign. However, in some cases, anaemia develops and this can lead to death of the foetus. Management depends on evidence of infection and the stage of the pregnancy but termination is not usually recommended as the risk of long-term foetal harm is low.

5. Genital herpes infection in pregnancy (Herpes simplex virus)

Babies delivered when the mother has an active genital herpes infection have a 40 per cent chance of acquiring this infection during the delivery and this infection can lead to serious neonatal illness and even death of the baby. (Maternal genital herpes infection is not a problem at other times during the pregnancy as it is not transmitted to the baby.)

Women with a past history of genital herpes infection need to make their obstetrician aware of this fact as the infection may recur during the pregnancy. (A first infection with genital herpes can also occur during pregnancy.) The infection appears as small groups of small, red lesions; they usually start off as small red blisters. It can be treated with a course of the antiviral drug acyclovir.

Caesarian section is recommended for women who have evidence of active genital herpes infection at the time of delivery.

6. HIV:

The incidence of HIV in pregnant women in Australia is low. However, if there is at high risk of being infected, the disease should be screened for. With good treatment, the risk of transmission to the baby is very low.

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Recommendations for women to minimise their risk of infection during pregnancy

  • Children in her household should be fully immunised
  • She should know her rubella and varicella immune status before pregnancy, and be offered vaccination if required.
  • Cutlery and toothbrushes should not be shared with young children
  • Hands should be washed before and after food preparation and before eating (very important in avoiding CMV)
  • Hands should be washed after changing nappies or handling body fluids of other young children (very important in avoiding CMV)
  • Undercooked meat should be avoided
  • Contact with cat faeces should be avoided
  • Gloves should be worn while gardening

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Dietary, drug and medication issues in pregnancy

1. Folate supplements and reducing the risk of neural tube defects

Increasing folate intake prior to becoming pregnant is the best way to reduce the risk of spina bifida and anencephaly. (Both are types of neural tube defects). These abnormalities occur in about 1 in 500 to 1,000 pregnancies (about 350 pregnancies each year) and they occur very early in the pregnancy; at about 20 days after conception. This is before the woman is even aware that she is pregnant!! About 70 per cent are found during routine testing early in pregnancy and the pregnancies are usually terminated.

Taking folate (a B group vitamin) supplements can reduce the incidence of neural tube defects by about 70 per cent. However, to gain this benefit, the folate needs to be started about two months before conception takes place and needs to be continued for three months after conception. For women who are not at increased risk of having a baby with a neural tube defect, the required dose of folate  is 0.5mg per day.

For women at increased risk, the dose is 5.0mg per day. This group includes women who:

There is also some preliminary evidence that folate supplements may protect against other diseases such as oral cleft palates and heart and kidney malformations and even early childhood cancers such as leukaemia. (These later benefits are definitely not established yet.)

Folate supplements should be taken in addition to a diet that is rich in folate.

While many Australian women are aware of the benefits of folate supplements, only about 50 per cent are taking such supplements at the time they conceive their child. An important reason for this is that, as stated before, about 50 per cent of pregnancies are unplanned. If you are a woman of child-bearing age, you should ensure that you have a diet high in folate, and, if there is any chance of you becoming pregnant, you should take folate supplements. Foods rich in folate include cabbage, peas, wholegrain cereals, brussel sprouts, lentils and lettuce.

About 50 countries have helped solve this folate deficiency problem by the supplementation of flour with folate. In Canada such supplementation has led to a 50 per cent drop in the incidence of neural tube defects. In Australia, commercial bread is fortified with folate (not organic bread), with 3 slices giving 0.13mg of folate. (Some cereals also are supplemented with folate.) This level of fortification is modest. While there is no doubt it will help reduce neural tube defects, it will not achieve desired early pregnancy levels in many women. Thus, women who are thinking of or planning to become pregnant should still continue take folate supplements.

2. Iodine deficiency

Insufficient dietary iodine intake is a problem for numerous Australians. The normal daily requirement of iodine is 150 micrograms and this rises to 200 micrograms in pregnant or lactating women, making them more likely to be deficient. This is a potential problem as significant deficiency in the foetus / neonate can lead to problems that include mild deficits in speech, movement, hearing and IQ. Most specialists recommend that women intending to become pregnant and pregnant and lactating women should take iodine supplements in doses of 150 to 200 micrograms per day. Such supplements are quite safe for normal women and should be commenced several months before becoming pregnant. Women who already have thyroid problems need to discuss supplementation with their doctor. Food sources include bread, seafood, eggs and dairy products.

3. Calcium and Vitamin D

Calcium reduces the risk of pre-eclampsia (high blood pressure) in pregnancy. The recommended daily intake for all women during their child bearing years is 1000mg per day. See section on Calcium for more details.

Vitamin D deficiency is common in women in Australia, especially in colder areas and in winter. Recent research has shown that at least 20% of healthy pregnant women have low vitamin D levels and the rate can be much higher in certain ethnic groups.

It is reasonable to screen all pregnant women for vitamin D levels (early in the pregnancy) as low vitamin D can affect both the mother (bone pain and weakness and an increased risk of diabetes in pregnancy) and the unborn child. It is safe for pregnant women to take vitamin D supplements when their administration is overseen by their doctor. For more detailed information on Vitamin D, see the Section on Vitamin D in the topic 'Fracture prevention'.

4. Avoid alcohol, smoking, caffeine and other social drugs

All social drugs should be avoided during pregnancy, especially in the first trimester. Unfortunately, the incidence of both tobacco use and problem alcohol-use is high in young women and continuing these behaviours during pregnancy will put the baby at risk.

Smoking: Smoking can cause pre-eclampsia and pre-term labour and also retard foetal growth. (Just one pack per day increases the risk of growth retardation by 50 per cent. However, if the woman can stop smoking by 16 weeks into the pregnancy there is no increase in risk to the pregnancy or foetus. 

Alcohol: Excessive alcohol intake can cause retarded foetal growth, microencephaly (small head) and dysmorphic features. It most commonly occurs in women who binge drink throughout the pregnancy but there is no general agreement on what is a safe level of consumption. Australian authorities advise not drinking at all or keeping consumption to one standard drink on a maximum of two days per week (Obviously binge drinking, i.e. consuming more than five standard drinks in one sitting, is definitely not recommended.) Most of the damage from alcohol occurs early on in the pregnancy and some so early that women are not yet aware that they are pregnant. Thus, if a woman is attempting to become pregnant, the no / very low alcohol consumption advice should be adopted from the time they start trying to conceive.

Caffeine: Caffeine should be restricted to no more than two cups of coffee or strong tea per day. Larger intakes are associated with an increased risk of miscarriage.

Illicit drugs: Illicit drug use is also very likely to be harmful. For example, cocaine use is associated with brain and limb abnormalities while heroin can cause dangerous narcotic withdrawal in the newborn.

5. Prescription and over the counter medications in pregnancy

Many medications can adversely affect the foetus and about two to three per cent of birth defects are due to medications. Thus, all maternal medications need to be reviewed prior to pregnancy and changes made where appropriate. Some common drugs that cause problems are tetracyclines, valproate (Epilim), ACE inhibitors, diuretics, lithium, vitamins A and D, methotrexate, warfarin, cyproterone and warfarin. (This is not a complete list.)

It needs to be emphasized that most of these medications only cause problems occasionally and in most cases the foetus will not be affected. Many factors influence the likelihood of a problem occurring, including the stage of the pregnancy the medication was taken and the dose consumed.
Pregnant women also need to be careful regarding over-the-counter medications. For example, aspirin and non-steroidal anti-inflamatory drugs such as iboprofin (Naprogesic etc), both commonly used pain relievers, can significantly increase the risk of miscarriage. Always talk to your doctor before taking medications when pregnant.

Women needing to take routine medications should discuss their best options with their medical practitioner before becoming pregnant. ‘Mothersafe’ is a very helpful advisory service for doctors and mothers regarding the safe use of medication use during pregnancy and lactation. It is run by the Royal Hospital for Women in Sydney (Ph: (02) 9382 6539 or 1800 647 848). Another good national information source is the Therapeutic Advisory Information Service, which is manned by hospital pharmacists and runs 9am to 5pm weekdays.

6. Occupational / household / social hazards

Exposure to dangerous substances at work and at home needs to be watched. Some examples include ionizing radiation and chemicals in the work place and at home, chemicals such as paint thinners and strippers, other solvents, and lead-based paints, which are often present in older houses. (Exposure occurs when renovating.)
Exposure to heat, such as in saunas etc, can adversely affect the baby and should be avoided

7. Other maternal illnesses that can affect the foetus

High blood pressure: Women with high blood pressure need to be monitored closely as they have a 25 per cent increase in the incidence of pre-eclampsia, placental abruption or intrauterine growth retardation. Some blood pressure medications (such as ACE inhibitors and diuretics) need to be avoided during pregnancy as they can cause birth defects.

Epilepsy: Women with untreated epilepsy have twice the normal incidence of congenital malformations, including cleft lip or palate, congenital heart defects, and neural tube defects. Thus it is important that epilepsy is well controlled before pregnancy occurs. Also, because of the increased risk of neural tube defects, all women with epilepsy should be taking a 5mg folate supplement per day (rather than the normal 0.5mg) before becoming pregnant. Finally, some anti-epileptic medications (e.g. valproic acid (Epilim)) can cause birth defects and other problems and it is important that the woman is changed from such medications before becoming pregnant.

Diabetes: Many of the complications of Type 1 diabetes worsen during pregnancy and good control is required to ensure the mother stays healthy.

Women with phenylketonuria: Most adults with phenylketonuria have gone off their low-phenylalanine diets because it was felt that their high serum levels of phenylalanine would not hurt their mature brain. However, the excess phenylalanine does cross through the placenta and causes severe mental retardation in the developing foetus. For normal foetal development, mothers with phenylketonuria need to resume their diet and ensure it gives good control of serum phenylalanine levels.

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Older mothers

Over recent times there has been an increasing tendency for women to commence their families later in life. The average age of women having a baby was 25 in 1971. In 2013, the average age of women having a baby was 30.1 yrs, with about 22% of mothers being over 35 years old. Most women have very good reasons for deciding to have their children relatively later in life and ‘older’ mothers may well be able to cope better with the mental and financial stresses associated with having children. However, the decision to delay having children does unfortunately increase the risk to the child and the pregnancy.

a. Fertility and age

At present in Australia the average age of mothers and fathers (at the birth of children) is 30.7 and 32.9 years respectively. A significant proportion of women who choose to leave having children into their mid to late thirties will have problems falling pregnant due to reduced male and / or female fertility that occurs with increasing age. (About 5% of Australian males have a fertility problem.) In all, up to one in six couples have some degree of infertility problem and in Australia in 2017 about 16,000 babies were born using IVF (in vitro fertilisation).

The changes of menopause actually start about 10 to 12 years before menopause occurs, with the reduction in egg (follicle) numbers accelerating from the age of 36 to 38. About 1% of the female population is menopausal by 40 years and 5% by 43 years; with many more being perimenopausal.

Seventy-five percent of normal 25-year-old couples trying to fall pregnant will do so within six months. This figure drops to about 25% in 35 to 39 year-old couples. For younger women, it is reasonable to attempt conception for 12 months before seeking medical help regarding the investigation of infertility. In women 35 years and older, a shorter period is advisable.

The fact that about 25% of women using IVF are over 40 years of age indicates that age-related infertility is becoming a large problem and inevitably a significant proportion of these couples are going to end up disappointed. Overall 21% of women having assisted reproductive technology (IVF etc) treatment will conceive in their first cycle but this figure drops to only 10% for women over 40 years of age. Only about 35% of all women successfully deliver a baby after multiple attempts at IVF and again this figue is significantly worse for older women. So age really does matter.

It important to note that some clinics are better than others.

For more information about ART, see boxed section. The disappointment associated with the failure of several attempts at ART can be considerable, especially considering the time and effort that is involved, and it is enough to test even the best relationships. (The IVF success rate (live bith) in 2017 was about 21% with each IVF cycle and about 34% of women are successful overall.)

In the end, however, the best way to avoid age related infertility and the inconvenience and expense of ART is to think twice before delaying pregnancy too long.

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How effective and costly is Assisted reproductive technology (ART)

ART can occur with the couple’s own ‘fresh’ embryo or with a donor embryo (frozen), egg or sperm as required.

Older women usually require significantly more cycles to achieve a pregnancy using ART and a significant proportion will not be successful.

For couples using their own ‘fresh’ embryo:

  • Women under the age of 30 years have a 44% of falling pregnant with the first cycle and a 69% to 93% chance by the seventh cycle.
  • Women aged 40 to 44 years have an 11% chance of falling pregnant with the first cycle and a 21% to 38% chance by the seventh cycle.

The use of donor eggs significantly increases the success rate of ART, especially in older women, but of course the baby does not then possess the mother’s genetic material. Other factors that affect success rates include ovarian (egg) reserve, previous successful child-bearing, duration of infertility, and the number of previous unsuccessful attempts at ART treatment.

The use of pre-implant genetic testing of embryos also improves success rates as it enables the excclusing of embryos with significant genetic abnormalities which would not be viable.

The cost of achieving a live birth using ART varies depending on whether frozen or fresh embryos are used and, as would be expected from the above, with age. Much of this expense is covered at present by the Australian Government.

Multiple births occur in about 20% of all deliveries following ART treatment in Australia.

 

b. Foetal abnormalities:
Chromosomal (congenital) abnormalities such as Down syndrome increase with maternal age and become significantly greater after the age of 35. The risk of such abnormalities occurring is four times the rate of women under 35 when maternal age is over 35 years and 10 times this rate when maternal age is over 40 years. The rate of miscarriage is greater after the age of 35.

c. Foetal death rate:
The foetal death rate, due to miscarriages, still-births and ectopic pregnancies, increases with increasing maternal age; especially after the age of 40. The rate at a maternal age of 22 is 9 per cent while the rates at 35 and 42 years of age are 20 per cent and 50 per cent respectively. This increase is partly due to the fact that more congenital abnormalities are occurring as maternal age increases and severe congenital abnormalities actually cause miscarriages and still births to occur.

d. Other abnormalities:
Other abnormalities that increase significantly after the age of 40 include gestational diabetes, placenta praevia, and placental abruption. Delivery by caesarian section is also greater after 40 years but this is at least partly due to doctor / mother preference rather than an increase in problems.

Having said this all this, most older mothers who look after their health well during their pregnancies deliver normal healthy babies and cope well themselves.

 

Stem cells and the storage of the cord blood of a newborn baby

Some hospitals offer the opportunity to store a newborn baby’s cord blood. This cord blood can be stored either privately for the exclusive use of the baby and his or her family or it can be stored in a public cord blood bank, where it is available for all the community to use; a bit like a normal ‘blood bank’.

Cord blood is a source of stem cells and the storage of these stem cells can be useful for two reasons. Firstly, they can be used for the treatment of children who suffer from several childhood diseases such as childhood leukaemia.

Secondly, it is hoped that these cells will prove to be useful in treating many diseases in the future, such as Parkinson’s disease and diabetes. Thus, they may be of use to the baby (or a relative) in later life.

It should be noted that stem cells can also be sourced from the bone marrow of adults and from embryos. There are fundamental differences between the different types of stem cells and they have different possible uses. This is a complex topic and further discussion is beyond the scope of this book. Your obstetrician should be able to provide further information if required.

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Reducing the risk of preterm birth

Preterm birth (delivery before 37 weeks) is the leading cause of perinatal mortality. In 75% of cases this occurs spontaneously. In the other 25% delivery is induced for medical reasons i.e. where the risk of continuing the labour is considered a greater risk than problems associated with early deliverey.

Some factors that incease the risk of spontaneous preterm delivery include:

The length of the cervix at 18-20 weeks, measured by ultrasound, is a good indicator of risk level; with a short cervix increasing the risk. Women with short cervixes can be treated with vaginal progesterone to reduce the risk of preterm delivery. Another option is putting a suture in the cervix. Pregnant women should discuss this issue with their obstetrician.

Physical activity during pregnancy

While there are restrictions on when during pregnancy exercise can be done and the type of exercise that can be done, current medical advice is that in an uncomplicated pregnancy, exercise is generally beneficial for women, whether they are currently 'exercisers' or not. Potential benefits include maintaining a healthy maternal weight, reducing the risk of gestational diabetes (diabetes in pregnancy) occurring and improved mental health / prevention of depression.

Importantly, it has been shown that exercise does not have an effect on birth weight and does not decrease blood flow to the uterus (and thus the foetus).

Suitable aerobic activities early on in pregnacy include running, walking, swimming, dance, yoga and aerobics classes. Generally speaking the exercise guidelines for the general population apply to healthy women; so 150 minutes per week of moderately intensive aerobic exercise.

Some general advice regarding

Contraindications to exercising during pregnancy

As stated above, any woman with a pre-existing medical condition should consult with their doctor regarding the limitations on exercise that the condition may place. Conditions that are especially important to discuss with a doctor before commencing exercise include: any heart or lung problem, arrhythmias, high blood pressure, diabetes, being extremely over-weight or extremely under-weight, musculoskeletal problems, epilepsy, thyroid disease and being a smoker.

Finally, any foetal abnormality may have an implications for exercise and needs to be discussed; for example intra-uterine growth restriction.

When to stop exercise and seek medical advice

 

 

 

 

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