Animal studies have revealed craniofacial malformations. In humans, use of drugs that act on the renin angiotensin system (RAS) during the second and third trimesters increases fetal and neonatal morbidity and death. There are no controlled data in human pregnancy.

US FDA pregnancy category D: There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

UK: Use is not recommended during the first trimester of pregnancy and is contraindicated during the second and third trimesters.
US: This drug should not be used during pregnancy unless there are no alternatives and the benefit outweighs the risk to the fetus.

US FDA pregnancy category: D (second and third trimesters); C (first trimester)

Comments: Adequate methods of contraception should be encouraged.

See references

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 (in small amounts [captopril, hydrochlorothiazide])

Comments: According to some authorities, this drug is not recommended in preterm infants and for the first few weeks after delivery, but may be considered for an older infant at the lowest possible dose if treatment is necessary to the mother and the child is closely observed. Other authorities indicate that captopril is not expected to cause adverse effects in breastfed infants and hydrochlorothiazide 50 mg/day or less is considered acceptable during lactation.

See references