Pregnancy and the older woman

It used to be that books and articles referred to women over 30 as "older mothers" - now, 30-something mothers are the norm. According to the National Centre for Health Statistics in the US, while only 4% of first-time mothers were over 30 in 1970, in 1987, nearly 16% of women who gave birth to their first child were 30 or older.

And this isn't just in the US. In fact, the trend of later pregnancies is evident in Singapore, too. According to a 2001 report by Dr George Yeo, senior consultant and head of the Department of Maternal Foetal Medicine at KK Women's and Children's Hospital, 16.8% of pregnancies here involve women over 35. And of these older mums, 2 out of 5 are first-timers.

Life changes and work pressures are some of the reasons why many women are putting off starting families. While the science of taking care of older mothers has improved, there are limits and certain risks still remain.

The Chromosome Risk

One of the biggest issues for older mothers is the risk of having a child with chromosomal abnormalities. The most common is Down's Syndrome, a condition that causes mental retardation and defects of the heart and other organs. The risk of giving birth to a child with this condition increases with the mother's age. A woman aged 25 has a 1 in 1500 risk while for one aged 45 and above, the risk is 1 in 30.

There are, however, 2 prenatal tests - amniocentesis and chorionic villus sampling (CVS) - that detect chromosome disorders. Both tests carry a slight risk of miscarriage. If your test findings are abnormal, you'll be faced with the difficult decision of whether to continue or terminate the pregnancy.

Top

Taking Care Of Yourself

Diabetes and high blood pressure are more common in women in their 40s. Diabetic mothers are at greater risk for pre-eclampsia, pre-term delivery, placental problems or stillbirth. The most common placental problem is placenta previa, in which the placenta covers part or all of the opening of the cervix.

A study at the University of California found that first-time mothers over age 40 were up to 8 times as likely as women in their 20s to have this complication. Placenta previa can cause severe bleeding during delivery, which can endanger mother and baby, but complications often can be prevented with a caesarean delivery.

Some studies suggest that women who delay having their first baby until age 35 or older are at increased risk of having a baby who is of low birth weight (less than 2.5kg) or premature (born at less than 37 full weeks of pregnancy). And these risks rise modestly but progressively with a woman's age, even if she does not have age-related chronic health problems such as diabetes and high blood pressure.

Women with diabetes are also more likely to have a child with poor foetal growth or birth defects. Blood pressure also normally rises during pregnancy, which can worsen an existing condition, putting you at risk of seizures or stroke.

Even if you don't have diabetes or high blood pressure, you have an increased chance of developing pregnancy-related diabetes (gestational diabetes) as well as pregnancy-induced hypertension (PIH). Both gestational diabetes and PIH increase the chances of eclampsia, a complication characterised by high blood pressure, swelling of your face and hands and protein in your urine. Eclampsia can impair your nervous system function, leading to seizures, stroke or other serious complications.

Both conditions occur infrequently and complications are rare. Gestational diabetes is controlled with diet and exercise (and insulin injections for about 15% of women). PIH is treated with bed rest and close monitoring of your condition as well as the baby's, both during pregnancy and delivery.

Top

Other Concerns

Your chances of having twins or triplets also increase with age. And this is without any fertility treatment which may increase the risk further. The possibility of multiple births puts the health of an older woman in jeopardy.

Your chances of caesarean delivery are also about 40% higher than a younger woman's. Although this type of delivery is more dangerous, it is usually uncomplicated and requires only a slightly longer hospital stay and recovery time at home.

Most miscarriages occur in the first trimester for women of all ages. However, the rate of miscarriage in older women is significantly greater. Studies estimate that this risk is about 12% to 15% for women in their 20s and rises to about 25% from age 40. The increased incidence of chromosomal abnormalities contributes to the age-related risk of miscarriage.

Top

Planning Ahead

There are some things you can do to improve the health odds for you and your baby:

• Control existing health problems such as high blood pressure or diabetes.

• Lose weight if you're overweight. Women who are overweight when they get pregnant are more likely to develop problems during pregnancy.

• Take pre-natal vitamins containing folic acid before getting pregnant to help prevent neural tube defects such as spina bifida, a condition in which the tissue over the baby's spinal cord doesn't close.
• Learn about your health risks and the diagnostic tests you may want to have to detect chromosome abnormalities.

Top

In The First Place

It's harder for an older woman to get pregnant, compared to a younger woman, other things being equal. The chance of having a problem with fertility increases from about 11% in your early 20s to about 33% in your late 30s to almost 40% in your early 40s. So if it takes the average younger woman 4 months to conceive, it may take an older woman twice that long. If you've had no luck getting pregnant naturally, you can increase your odds of carrying and delivering a healthy baby to about 10% with a fertility-enhancing treatment.

Top

The Benefits Of Waiting

Although later-age pregnancy can put you at higher risk for a number of health complications, there's an upside. As a potential older mother, you may be more mature, realistic and dedicated to the idea of having a baby than a woman in her 20s. You've probably also given a lot of thought to the changes a new baby will bring.

Top

Article extracted from Panpac Lifestyle Magazines from 2000 to 2003.