Congenital heart defects are the most common kind of birth defect, and new research shows that there's a link between babies developing the defect and high blood sugar levels in the first trimester of pregnancy.
About 8 out of 1,000 babies are born with congenital heart defects, which can range from mild to severe and life-threatening, according to the National Institutes of Health.
Researchers at Stanford University followed roughly 19,000 women, testing their blood sugar levels during the first trimester of pregnancy. Dr. Emmi Helle, the leader of the study, and her team found that for every 10 milligrams per deciliter increase in blood sugar, the risk of the baby being born with a congenital heart defect rose about 8 percent.
Researchers said this particular test was much better at determining the link between the mother’s blood sugar and relationship to heart defects than the standard oral glucose tolerance test (the dreaded orange drink) usually used to diagnose gestational diabetes. But the orange drink is given long after the first trimester ends—between 24 and 28 weeks of pregnancy.
Ultimately, the new research shows that blood sugar levels should be monitored at the beginning of pregnancy, so the mom can get aggressive treatment earlier if necessary—which will eventually mean lower rates of heart defects in infants in the long run.
Dr. Barry Goldberg, the chief of pediatric cardiology at Northwell Health’s Southside Hospital in New York, said that while the study is encouraging, more research needs to be done in this area. While gestational diabetes can be controlled with diet and occasionally meds and insulin, the risk of congenital heart defect is still high.
Although the study could not prove what caused the increase, researchers say this is the first study that shows a significant link between the mom’s high blood sugar and congenital heart defects. And, Goldberg says, the findings "may have a profound effect on how pregnant women are screened and treated for diabetes during pregnancy" in the future.