Over 35 and pregnant? What you need to know

Approximately 20 percent of women in the United States have their first baby after age 35, and if you’re pregnant or trying to conceive, you might be worried about having a healthy pregnancy and a healthy baby.

After 35, a woman has a higher chance for having a baby with trisomy 13, 18 and 21.  Trisomy 21 is also known as Down syndrome, a condition that affects one in every 691 babies in the United States, according to the National Down Syndrome Society.

Down syndrome is a big concern for women. According to a recent survey by Ariosa Diagnostics, more than 50 percent of women said they were worried about Down syndrome and other genetic conditions.

At age 30, the chances of having a baby with Down syndrome are about one in 900 and at age 35, they increase to one in 300. Yet “the majority of babies with Down syndrome are born to women under age 35,” according to Dr. Genevieve Fairbrother, an obstetrician and gynecologist in Atlanta, Ga.  She said that although the individual risk is lower, more women under 35 are having babies.

Also, women over 35 who become pregnant have an increased risk for gestational diabetes, pre-eclampsia, placental abruption and placenta previa. They’re also more likely to be overweight and have high blood pressure, diabetes and thyroid disease.

If you’re over 35, here are some things you should consider:

Lose weight and get healthy

“There’s no magic threshold about 35,” Fairbrother said, who added that aside from genetic problems, most women who give birth after 35 will be fine. Yet many complications can be prevented with simple lifestyle choices. So if you have diabetes, thyroid disease or are overweight, get your health under control. And if you drink or smoke, stop immediately.

Take a prenatal vitamin

Starting a prenatal vitamin with at least 1 milligram of folic acid for at least three months before getting pregnant and continuing through pregnancy can help prevent neural tube defects like spina bifida.

Get an ultrasound at 6 weeks

Most providers won’t do an ultrasound until eight weeks, but if you’re over 35, you should consider an ultrasound at six weeks, according to Dr. Sara Gottfried, an obstetrician and gynecologist in Berkeley, Cali., and author of the New York Times bestseller The Hormone Cure. If you’re considering first trimester genetic screening, an early ultrasound can help you get ahead of the game and can also look for placenta previa – a condition that occurs when the placenta cover’s the mom’s cervix.

Get screened for high blood pressure

Since blood pressure drops in the second trimester, it’s important to have your blood pressure measured in the first trimester to determine your risk for pre-eclampsia. “You don’t want to miss that window,” Gottfried said.

Decide on genetic tests early

Before getting pregnant or as soon as you know you are, it’s important to decide if you want to have genetic testing.  Tests like chorionic villus sampling (CVS) need to be done early, usually around 11 weeks.

“I think one of the important pieces for a woman to understand (is) what her values are and what kind of testing she wants to do, because the timing of it can come up pretty fast,” Gottfried said.

Consider the risks

At age 35, you have the same risk of having a miscarriage or other issue if you have an amniocentesis as you do having a baby with a genetic problem. An amniocentesis is a prenatal diagnostic procedure that involves using a needle to take a sample of amniotic fluid surrounding the fetus. According to the Ariosa Diagnostics survey, 58 percent of women over 35 would avoid an amniocentesis. 

If you’re concerned, you might want to consider the new, non-invasive, and extremely accurate cell-free DNA tests. “I think every couple has to ask themselves, ‘How are we going to use this information, how accurate is it, how important is it for us, what level of certainty do we need to know?’” Fairbrother said.

Get screened for gestational diabetes

Gottfried recommends women over 35 get an early screening glucose loading test done at the first prenatal appointment to look for high blood sugar.  Women should then repeat the test between 24 and 28 weeks.

Eat right and exercise

“Pregnancy is a stress test on your body,” Fairbrother said. And gaining too much weight can increase your risk for gestational diabetes, weight problems and for having an overweight child.

Aim to eat an extra 200 to 300 calories a day, and be sure to eat plenty of lean proteins, fruits, vegetables, whole grains, low-fat dairy and healthy fats. Also, 30 minutes or more of exercise on most days is ideal.

Julie Revelant is a freelance writer specializing in parenting, health, food and women's issues and a mom.