Heartburn drugs before pregnancy may increase risk for birth defects

Women who use heartburn medication during pregnancy should not be overly concerned about the drugs causing birth defects, but using the drugs before they become pregnant may cause problems for the unborn child, according to a new study from Denmark published in the New England Journal of Medicine.

The study looked at nearly 841,000 births registered with national databases from 1996 to 2008. In about 5,000 cases, the mothers had taken PPIs at some point during the four weeks prior to pregnancy through their first trimester. Overall, 3.4 percent of the babies whose mothers took PPIs had a major birth defect, compared to 2.6 percent of babies whose mothers did not take the drugs. Researchers said this difference was not significant enough to cause alarm.

However, the study showed that women who took PPIs in the four weeks leading up to pregnancy had a 39 percent greater risk of having a baby with major birth defects. The study’s authors dismissed the findings as biologically implausible as the medication generally does not stay in the body for more than a few hours.

The study does raise questions about the safety of heartburn medications during pregnancy. Gastrointestinal problems are one of the most common side effects with pregnancy. In some cases, over-the-counter medications cannot quell nausea and vomiting, raising the mother’s risk for dehydration and other serious problems.

Some doctors have turned to prescribing Reglan (metoclopramide). While the drug is not approved by the FDA for use during pregnancy, it has been prescribed for off-label use.  Some foreign studies suggest it does not raise a woman’s risk for having a baby with birth defects. The drug, however, carries a black box warning of the risk of developing a serious involuntary movement disorder called Tardive Dyskinesia.