Women's Health

ACE Inhibitors May Boost Birth Defects

About the Study

The study was conducted by William Cooper, MD, MPH, and colleagues. Cooper works in the pediatrics department of Vanderbilt University's medical school.

Cooper's team studied data on 29,507 babies born between 1985 and 2000 who were enrolled in Tennessee's Medicaid system.

The researchers checked the mothers' records for prescriptions filled during the first trimester of pregnancy for ACE inhibitors or other high blood pressurehigh blood pressure drugs (antihypertensive medications). They also checked the babies' records for major birth defects not linked to genetics.

Most babies weren't exposed to any high blood pressure drugs during the first trimester.

However, 411 babies were exposed to high blood pressure drugs during the first trimester alone. Of those babies, 209 were only exposed to ACE inhibitors during pregnancy's first trimester. The other 202 babies had been exposed to other high blood pressure drugs during the first trimester.

Measuring Risk

A total of 856 babies were born with birth defects. That's nearly 3% of the overall group.

Eighteen babies with first-trimester exposure to ACE inhibitors -- about 7% of all babies in that group -- were born with birth defects, the study shows. That's more than twice the rate of babies unexposed to any high blood pressurehigh blood pressure drugs.

Babies exposed in the first trimester to high blood pressure drugs that weren't ACE inhibitors weren't at higher risk of major birth defects than those with no exposure to any blood pressure drugs, according to the study.

"We found that fetal exposure to ACE inhibitors restricted to the first trimester of pregnancypregnancy, an exposure that was previously considered to be safe, was associated with a risk of a major congenital malformation that was 2.7 times as great as the risk with no fetal exposure to ACE inhibitors or other antihypertensive medications," write Cooper and colleagues.

The study was observational, so the results don't prove that ACE inhibitors caused birth defects.

It's possible that some women filled their prescriptions without taking the drugs, the researchers note. Because diabetesdiabetes can raise the risk of birth defects, none of the mothers included in the study had diabetes.

Three of the researchers (but not Cooper) report having received grants, served on advisory or drug safety monitoring boards, or consulted for drug companies, the journal notes.