-Use should be avoided.
-According to some authorities: Use is contraindicated.

AU TGA pregnancy category: D
US FDA pregnancy category: Not assigned.

Risk summary:
-Based on the mechanism of action and findings in animals, this drug can cause fetal harm when administered to a pregnant woman.
-In animal studies, this drug was embryotoxic and teratogenic.

Comments:
-If this drug is used during pregnancy, apprise the patient of the potential risk to the fetus.
-In early pregnancy, this drug is known to increase intrauterine pressure and cause uterine contractions. It may also reduce uterine blood flow.

In animal studies, this drug at doses lower than the maximum recommended human dose of 4 mg/day caused a marked decrease in blood flow to the uterus and placenta in pregnant guinea pigs. In rabbits, this drug was embryotoxic and teratogenic (increased resorptions, increased implantation loss, fetal anomalies, and fetal deformities). In a rat fertility study, decreased litter size was seen. Testicular atrophy and disturbances of spermiogenesis were also seen in male rats. Based on animal studies, there is associated risk of reduced fertility with the use of this drug. Administration of a single intravenous dose of this drug to pregnant women during the first trimester induced uterine contractions and endometrial ischemia.

AU TGA pregnancy category D: Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details.

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.

See references

Safety has not been established. A decision should be made to discontinue breastfeeding or discontinue the drug, considering the importance of the drug to the mother.

Excreted into human milk: Data not available
Excreted into animal milk: Data not available

Comments:
-This drug should not be used by women who are breastfeeding.
-The effects on milk production and nursing infants are unknown.

See references