Every new mother hopes to see 10 perfect little fingers and toes, and to hear the words, “You have a healthy baby.” Unfortunately, it doesn’t always happen. According to the March of Dimes, about 150,000 babies are born with birth defects each year in the United States. Some defects, such as cystic fibrosis, spinal muscular atrophy, and sickle cell disease, are inherited. But others can be avoided, and the more a mother knows about the topic, the better prepared she can be for a healthy delivery.
“Birth defects are abnormalities of structure, function or body metabolism that can lead to mental or physical disabilities,” says Dr. Teresa Knight, CEO of Women’s Health Specialists of St. Louis. There are more than 4,000 known birth defects, ranging from minor to serious, she notes. Although many are treatable, some can be fatal: birth defects are the leading cause of death in the first year of life.
“Some abnormalities, such as cystic fibrosis or Tay-Sachs, can be caused by genetic factors—a single missing or faulty gene can cause a defect,” Knight says. “Others can be caused by environmental factors, such as exposure to certain diseases or drugs; and some, such as spina bifida, heart defects and cleft lip and palate, can be caused by a combination of genetic and environmental factors.”
One of the leading risk factors for birth defects today is diabetes, which is controllable, Knight points out. “We’re seeing so many cases of diabetes lately because of the obesity epidemic,” she says. “Women with poor blood-sugar control are several times more likely to have a baby with a serious birth defect. Before you try to conceive, you should absolutely make sure your diabetes is under control.”
There are a number of other things a woman can do before and during pregnancy to reduce her risk of having a baby with a birth defect. “Get a pre-conception health check-up, particularly if you have a family history of birth defects or a chronic health condition like diabetes, high blood pressure or epilepsy,” Knight says.
Routine prenatal screening can help determine if the mother has an infection or other condition that is dangerous to the fetus, and it can also help determine if the fetus has certain birth defects, says Susie Gaffney, a women’s health nurse practitioner at Saint Louis Associates in OB/GYN. Screening methods include ultrasound, chorionic villus sampling (CVS) and amniocentesis. “An ultrasound paired with a blood test early in pregnancy—between 11 and 14 weeks of gestation—is about 90 percent accurate in predicting some abnormalities,” Gaffney says. “An anatomical ultrasound at about 20 weeks measures the fetus’ head, brain, heart and stomach development. Ultrasound results can indicate if further testing is needed.”
If so, CVS, which can be done at about 16 weeks, and amniocentesis, done at about 20 weeks, can diagnose or rule out chromosomal problems such as Down syndrome and many genetic defects. “Both are ways of sampling the baby’s DNA,” Gaffney explains. “CVS is slightly riskier, but can be done earlier.”
But with all that can go wrong, it’s reassuring to know that many environmental birth defects are avoidable. “You just need to take precautions during, and preferably before, pregnancy,” Gaffney says. Precautions include making sure all the mother’s vaccinations are up to date; maintaining a healthy diet; avoiding fish that contain high levels of mercury; taking prenatal vitamins with plenty of folic acid—which prevents neural tube defects such as spina bifida; and abstaining from smoking, alcohol and illegal drugs. “And don’t take any drugs at all without checking with your doctor, including natural supplements,” she adds.
Gaffney recommends preconception counseling for all women who are considering becoming pregnant. “It’s the best way of learning how to decrease the risk of avoidable birth defects,” she says. “And, if you have a family history of birth defects, or if later testing reveals that your child has an abnormality, you’ll have time to prepare and learn about available resources.”