There are no studies on the placental transfer or teratogenicity of this drug. It does cross the placenta in small amounts, although not enough to be embryotoxic. Prolonged vasoconstriction of uterine vessels and/or increased myometrial tone may lead to reduced myometrial and placental blood flow which may have accounted for the fetal growth retardation that has been observed in animal studies. This drug should not be used during labor and delivery due to its oxytocic effect which is maximal in the third trimester. There are no controlled studies in human pregnancy.

US FDA pregnancy category X: Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits.

Use is contraindicated

FDA pregnancy category X

Comments:
-May cause fetal harm; if used during pregnancy or pregnancy occurs while taking this drug, the patient should be apprised of the potential hazards to the fetus.

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A decision should be made to discontinue breast-feeding or discontinue the drug, considering the importance of the drug to the mother.

Excreted into human milk: Yes

Comment: This drug should not be used while breastfeeding due to the potential for serious adverse events in nursing infants.

This drug is excreted in human breast milk and may cause vomiting, diarrhea, weak pulse, and unstable blood pressure in the nursing infant. Ergot drugs are known to inhibit prolactin although there are no reports of decreased lactation.

See references