Epidemiological data have failed to reveal evidence of an increased risk of congenital malformations or other outcomes when patients took this drug during the first trimester. Animal models have revealed evidence of bone morphology changes in offspring exposed to high doses throughout pregnancy and lactation.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

This drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.

US FDA pregnancy category: Not assigned.

Risk Summary: There are no data available on use of this drug in pregnant women to inform of a drug-related risk.

See references

Following an oral dose of 20 mg, the peak concentration of omeprazole in breast milk was less than 7% of the mother's peak serum concentration, or a dose of approximately 0.004 mg of omeprazole in 200 mL of milk.

Use is not recommended and a decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.

Excreted into human milk: Yes (omeprazole); Data not available (sodium bicarbonate)
Excreted into animal milk: Data not available (sodium bicarbonate)

Comments:
-This drug may cause serious adverse events and/or tumorigenicity in breastfed neonates and infants.
-The American Academy of Pediatrics (AAP) state that omeprazole should be avoided until additional studies can confirm the safe use of this drug during breastfeeding.
-The AAP state that chronic or indiscriminate use of sodium bicarbonate is not recommended during breastfeeding.

See references