Pregnancy: Adequate and well-controlled studies in humans have not been done and the drug is not recommended.
Studies in pregnant rats did not show omeprazole to have any teratogenic potential at doses 345 times the human dose. Omeprazole produced dose-related increases in embryo-lethality, fetal resorptions, and pregnancy disruptions in rabbits receiving 17 to 172 times the human dose.
In rats, dose-related embryo/fetal toxicity and postnatal developmental toxicity were observed in offspring resulting from parents treated with 35 to 345 times the human dose.
FDA Pregnancy Category C.
Breast-feeding: It is not known whether omeprazole is distributed into human breast milk. However, because omeprazole has been shown to cause tumorigenic and carcinogenic effects in animals, a decision should be made on whether nursing should be discontinued or the medication withdrawn, taking into account the importance of the omeprazole to the mother.