Animal studies with hydrochlorothiazide have failed to reveal evidence of teratogenicity. Animal studies with spironolactone have revealed evidence of teratogenicity. There are no controlled data in human pregnancy.

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.

This drug should not be used during pregnancy unless the benefit outweighs the risk to the fetus.

US FDA pregnancy category: C

See references

Spironolactone has been found to be tumorigenic in rats.

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 (hydrochlorothiazide); Data not available (spironolactone, but canrenone which is a major and active metabolite of spironolactone, is excreted into human milk)
Excreted into animal milk: Data not available (spironolactone)

See references