- Women who are pregnant or breastfeeding. Pregnant women are excluded from this study because pravastatin is a lipid-lowering agent with the potential for teratogenic or abortifacient effects. It is not known whether pravastatin is excreted into human milk; however, a small amount of another drug in this class does pass into breast milk. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with pravastatin, breastfeeding should be discontinued if the mother is treated with pravastatin.