Women with thyroid disease are more likely to give birth to babies with heart, brain and kidney defects even if the thyroid function tests are normal during the pregnancy, according to new research from Johns Hopkins.
Results of the study, presented Jan. 17 at the annual meeting of the Society for Maternal-Fetal Medicine, showed that babies born to women with overactive or underactive thyroid also were at increased risk of a variety of other anomalies, including cleft lip or palate, or extra fingers. In addition, infants born to women with underactive thyroid were at increased risk of cardiac problems even if the mothers were on medication.
The research contradicts some earlier studies indicating thyroid disease did not pose fetal risks, but those studies were conducted using less sophisticated technology for detecting birth defects, says David A. Nagey, study co-author and associate professor of gynecology and obstetrics.
"We already knew that there was an increased risk of
problems, mostly intellectual or developmental, in children
as a result of hypothyroid (underactive thyroid)
pregnancies, but the link with birth defects is new and
unexpected," Nagey says. "If these results are confirmed, it
could lead to routine testing of women for thyroid disease
prior to pregnancy and for cardiac anomalies in the fetuses
of women with hypothyroidism."