Is Omeprazole Safe for Pregnant Women?
Yes, omeprazole is considered safe for use during pregnancy, with available epidemiologic data failing to demonstrate an increased risk of major congenital malformations or other adverse pregnancy outcomes. 1
Evidence from FDA Drug Labeling
The FDA label for omeprazole provides reassuring data based on multiple large epidemiological studies:
No increased risk of major birth defects: Four published epidemiological studies compared congenital abnormalities in infants exposed to omeprazole versus controls, showing no significant increase in malformation rates. 1
Swedish registry data (955 infants): The overall rate of malformations, low birth weight, low Apgar scores, and hospitalizations in omeprazole-exposed infants was similar to the general population, though a slightly higher number of ventricular septal defects and stillbirths was noted (likely random variation). 1, 2
Danish cohort study (1,800 first-trimester exposures): Birth defect rates were 2.9% in omeprazole-exposed infants versus 2.6% in unexposed infants—essentially equivalent. 1
Prospective cohort (113 women): Major congenital malformations occurred in 4% of omeprazole-exposed pregnancies versus 2% in non-teratogen controls and 2.8% in disease-paired controls—no statistically significant difference. 1, 3
Key Safety Parameters
Outcomes showing no increased risk with omeprazole use:
- Major congenital malformations 1, 3, 4, 5
- Spontaneous abortions 3
- Preterm deliveries 3
- Low birth weight 3, 2
- Gestational age at delivery 3
- Mean birth weight 3
Important Caveats
Animal data considerations: While human data is reassuring, animal studies showed dose-dependent embryo-lethality at doses 3.4 to 34 times the human dose, though no teratogenicity was observed. 1 These findings have not translated to human experience at therapeutic doses.
Recent signal detection study: A 2025 FAERS database analysis identified potential disproportionality signals for postpartum hemorrhage, fetal growth restriction, and pre-eclampsia with omeprazole. 6 However, this is exploratory pharmacovigilance data from spontaneous reporting and should be interpreted cautiously—it generates hypotheses but does not establish causation and is subject to significant reporting bias.
Dental morphology concern: A 2023 murine study found increased teeth morphological abnormalities in offspring exposed to omeprazole in utero. 7 This has not been validated in human studies and remains a theoretical concern requiring further investigation.
Clinical Recommendation
Omeprazole can be used throughout pregnancy when clinically indicated for acid-related disorders. The extensive human epidemiological data spanning multiple large cohorts provides substantial reassurance regarding its safety profile. 1, 3, 2, 4, 5 The background risk of major birth defects in the general U.S. population is 2-4%, and omeprazole use does not appear to increase this baseline risk. 1
For pregnant women requiring acid suppression therapy, omeprazole represents a reasonable first-line option with well-established safety data, though H2-receptor antagonists remain alternative options if preferred. 5