The safety of omeprazole during pregnancy: A multicenter prospective controlled study

OBJECTIVES: Our purpose was to determine whether omeprazole use during pregnancy is associated with an increased risk of malformations, spontaneous abortions, decreased birth weight, or perinatal complications. STUDY DESIGN: In a multicenter, prospective controlled study, pregnant women exposed to omeprazole during gestation were matched with controls exposed to nonteratogens and with disease-paired controls who used histamine blockers for similar indications. The primary end point was the incidence of major malformations. RESULTS: One hundred thirteen pregnant women were exposed to omeprazole during pregnancy. Rates of major malformations in the omeprazole group (4%) did not differ from controls exposed to nonteratogens (2%) (P=.68, relative risk=1.94, 95% confidence interval 0.36 to 10.36) and disease-paired controls (2.8%). Birth weight, gestational age at delivery, preterm deliveries, and neonatal complications were comparable among the three groups. CONCLUSIONS: No association was found between exposure to omeprazole during the period of organogenesis and increased risk for major malformations. Exposure throughout pregnancy is not associated with increased risk of spontaneous abortions, decreased birth weight, or perinatal complications.