Proton-pump inhibitors taken by expectant mothers during the first trimester are not associated with major birth defects in the offspring, according to a New England Journal of Medicine study.

Researchers used Danish registries to identify roughly 5000 women who filled prescriptions for PPIs in the 4 weeks before conception through the first trimester of pregnancy. Omeprazole was the most commonly prescribed PPI.

PPI exposure during the first trimester was not associated with increased risk for major birth defects, compared with no exposure. However, PPI use in the 4 weeks before conception was associated with higher risk for major birth defects (adjusted odds ratio, 1.39). The authors and an editorialist say unmeasured confounding likely explains the latter result.

Given that the pre-conception risk was lowest with omeprazole, the editorialist suggests it may be “the PPI of choice” for women of childbearing potential.

source: NEJM