High Risk Pregnancy

Advanced Maternal Age

Advanced maternal age is defined as any expectant mother who will have made her 35th birthday by the time she delivers. Although this is the usual definition in the medical literature, it must be remembered that nothing happens suddenly on the midnight of your 35th birthday!! What I mean is that the risks or problems associated with increasing maternal age start earlier (approximately 30 years of age) and even between the ages of 30-35, there is a slight increase in risks (for instance, your risk of having a baby affected with Down Syndrome).

In modern times, with women playing important roles in their careers, they have to delay having babies in order to achieve these positions. Hence, these highly intelligent, motivated and successful set of women find themselves labeled as ‘advanced age’ mothers! Indeed, they constitute a high-risk group with their own set of risk factors in pregnancy and delivery.

Down Syndrome

This is the most common chromosomal abnormality found in live born babies. The general occurrence of this condition is approximately 1 in 1000 births. However, its frequency is directly related to maternal age, as can be seen in the table below.

Maternal Age at Delivery
Risk at Term
32
1/725
33
1/592
34
1/465
35
1/365
36
1/287
37
1/255
38
1/177
39
1/139
40
1/109
41
1/85
42
1/67
43
1/53
44
1/41
45
1/32
46
1/25
47
1/20
48
1/16
49
1/12

At 40, the chance of Down Syndrome is 1 in 109. However, as can be seen, there is a steady rise in the risk and it is important to remember that ‘low’ risk is not ‘no risk’.

The reason that chromosomal problems go up with advancing maternal ageis because the egg a woman conceives with, is as old as she is. Every woman was born with all of the eggs she ovulates with for the rest of her post-pubescent, pre-menopausal life. So if you’re 25, and your Mom was 25 when she conceived you, then you’re the product of an egg that developed 50 years ago!

So what should I do to prevent / avoid a Down Syndrome baby?

Screening tests – It is important to undergo certain screening tests like Nuchal translucency screening with biochemical markers in your blood. This test, also called as First trimester screening, is carries out between 11-13 weeks of pregnancy. It is important to have it performed by practionners who are well versed and certified in performing these tests. The Fetal Medicine Foundation (FMF) is the charity that trains and audits practionners from all over the world in this technique.

Look for a FMF certified sonologist or fetal medicine expert in your area and they would be the best person to perform this test for you.

Diagnostic tests – While the screening tests can tell you your risk of carrying an affected baby, they are not able to give you a ‘yes or no’ type answer. In practice, what is done is that the screening test is performed first and then if the risk is ‘high’ (above 1 in 300) then a further diagnostic test is advised.

The diagnostic tests are – amniocentesis or chorionic villous sampling.

For more information on the above test, please contact us

Twins

Identical (monozygotic, or twinning from a single egg–”identical”) twins happens once in 250 pregnancies. This is unaffected by age, race, or any other factors. Dizygotic twins (twins from fertilization of two eggs), are more frequent in older mothers. They are also increased with the use of ‘fertlity drugs’ and artificial reproduction techniques (IVF, ICSI, etc).

Other Risks

  • Pregnancy-induced Hypertension
  • Gestational diabetes
  • Placental abruption
  • Increased risks of fibroids and the problems they cause in pregnancy
  • Increased risk of Ceasarean section / assisted births