What are the risks of having a baby if I'm 35 or older?

via babycenter.com

Expert Answers
George Mussalli, maternal-fetal medicine specialist

The main concern you face as you age is that your risk of conceiving a baby with a chromosomal problem goes up every year. For example, the risk of having a baby with Down syndrome rises from about 1 in 759 at age 30 to 1 in 302 at age 35, 1 in 82 at age 40.

If you'll be 35 or older on your due date, you'll be offered genetic counseling. A genetic counselor can help you understand your particular risks and help you decide whether to have genetic testing to screen for or diagnose chromosomal problems or other birth defects. Keep in mind that every woman has a chance of having a baby with problems, no matter what her age.

Other than that, if your weight is normal and you have no medical disorders, your risk of complications during the pregnancy is probably similar to that of younger women who are also in good health.

That said, the older you are when you get pregnant, the more likely you are to have a chronic disease, such as high blood pressure or diabetes, that may be undiagnosed and can affect your pregnancy.

You're also at higher risk of developing certain complications during pregnancy such as gestational diabetes, preeclampsia, placental abruption (in which the placenta prematurely separates from the uterine wall), and placenta previa (in which the placenta lies low in the uterus, partly or completely covering the cervix).

What's more, research shows that your chances of having a low-birthweight baby (less than 5 1/2 pounds) or a premature delivery increase with age. Some studies show that older women are more likely to need pitocin during labor, and most studies show a significantly higher rate of delivery by cesarean section.

Finally, researchers have found a higher risk of stillbirth and maternal death in women who give birth at 35 or older (though the overall number of stillbirths and women who die in childbirth each year has dropped significantly in the United States in the last few decades). The increased risk of these problems is largely due to underlying medical problems more common in older women. Proper diagnosis and treatment will help reduce the risks for both you and your baby.

The biggest obstacle for women age 35 or older may be getting pregnant in the first place. Fertility rates begin to decline gradually at age 30, more so at 35, and markedly at age 40. Women 45 and older rarely get pregnant without some kind of fertility treatment. Even with fertility treatments such as in vitro fertilization, women have more difficulty getting pregnant as they age. They also have more trouble staying pregnant: The rates of miscarriage and ectopic pregnancy go up substantially with age.

On the other hand, more women are having babies later in life in the United States than ever before. In the year 2000, the rate of birth among women 35 to 39 years old was up 30 percent from 1990. In women ages 40 to 45, the increase was 47 percent, and for those ages 45 to 49, the rate was an astounding 190 percent higher.

If you're considering getting pregnant, see your doctor or midwife for a thorough examination. She'll take a detailed medical and family history of both prospective parents to identify conditions that might affect your pregnancy or your chances of getting pregnant. You can manage many of the risks of pregnancy at 35 or older by seeing your doctor or midwife regularly for good prenatal care.

Editor's note: Don't be surprised if you notice differing statistics for the chances that a pregnant woman of a certain age is carrying a baby with Down syndrome.

For one thing, many of these babies are miscarried along the way, so the odds change as pregnancy progresses. For example, a 35-year-old woman has a 1 in 250 chance of carrying a baby with Down syndrome at 12 weeks gestation. But the odds go down to 1 in 300 at 20 weeks — which is about when you might have amniocentesis — and to 1 in 356 at 40 weeks.

These numbers can also vary widely depending on the source of the information. The numbers we use on BabyCenter are from a reference book published by the Fetal Medicine Foundation: The 11 — 14-week scan: The Diagnosis of Fetal Abnormalities, by Kypros H. Nicolaides, Neil J. Sebire, and Rosalinde J.M. Snijders (Parthenon Publishing Group. New York, NY, 1999).