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Health & Pregnancy

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Acid-Reducing Drugs May Not Be Risky in Pregnancy

Study Shows Proton-Pump Inhibitors Do Not Cause Birth Defects When Used in First Trimester
WebMD Health News
Reviewed by Laura J. Martin, MD

Nov. 24, 2010 -- The popular over-the-counter and prescription acid-blocking drugs proton-pump inhibitors (PPIs) do not appear to increase risk of birth defects when taken during the first trimester of pregnancy, a study shows.

In the study, 2.6% of more than 840,000 live births occurring in Denmark from January 1996 through September 2008 involved major birth defects. The study showed that 3.4% of 5,082 infants whose mothers took PPIs during the four weeks before conception through first trimester were diagnosed with a major birth defect. By contrast, 2.6% of 835,886 infants whose moms did not take these acid-reducing drugs during the same time period were diagnosed with a major birth defect.

The study is published in the New England Journal of Medicine.

The researchers did an analysis of the study data on PPI use limited to the time period during the first trimester of pregnancy. Statistically speaking, there was no significant increased risk of birth defects seen among children of women who took PPIs -- including Aciphex, Nexium, Prevacid, Prilosec, and Protonix -- during their first trimester of pregnancy compared with women who did not take these drugs during the first trimester of pregnancy.

“We found no significant association between the use of PPIs during the first trimester of pregnancy and the risk of major birth defects,” conclude study researchers Björn Pasternak, MD, PhD and Anders Hviid of Statens Serum Institut in Copenhagen, Denmark.

“This is the biggest and best study to date, and it is generally reassuring about use of PPIs in pregnancy,” says Allen A. Mitchell, MD, director of the Slone Epidemiology Center at the Boston University Medical Center in Boston. Mitchell wrote an editorial accompanying the new report.

That said, more studies are needed to support the safe use of PPIs during pregnancy, he says.

An Obstetrician’s Perspective

The new study “confirms the results of previous studies that did not show an increase risk in major congenital anomalies, [but] the study is limited because they used filled prescriptions as a definition of drug exposure and the information about birth defects is acquired from a registry, which may be subject to misclassification,” says Shari Gelber, MD, PhD, an ob-gyn at Weill Medical College of Cornell University in New York City, in an email.

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