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

AU TGA pregnancy category: B3
US FDA pregnancy category: Not assigned.

Risk summary: This drug can cause fetal harm when administered to a pregnant woman; no data available on use of this drug in pregnant women.

Comments:
-If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus.
-Patients of childbearing potential should use effective contraception during therapy.
---Coadministration of this drug with ethinyl estradiol 35 mcg-norethindrone 1 mg (oral contraceptive) results in an interaction between the 2 drugs, but is unlikely to reduce contraceptive effect; patients should be monitored for side effects associated with oral contraceptives and this drug.

Animal studies have revealed evidence of teratogenicity, fetotoxicity, and embryolethality. In pregnant rats administered this drug orally during organogenesis, increased incidences in hydronephrosis and hydroureter were observed at 10 mg/kg/day or greater (about 0.3 times the recommended human dose [RHD] based on mg/m2), and cleft palate was observed at 60 mg/kg (about 2 times the RHD based on mg/m2); reduced ossification of sacral and caudal vertebrae, skull, pubic, and hyoid bone, supernumerary ribs, anomalies of the sternebrae, and dilatation of the ureter/renal pelvis were also seen at 10 mg/kg or greater, but there was no evidence of maternal toxicity at any dose. In pregnant rabbits administered this drug orally during organogenesis, increased postimplantation loss and decreased fetal body weight (associated with maternal toxicity [decreased body weight gain and food intake]) were observed at 100 mg/kg/day (6 times the RHD based on mg/m2); fetal skeletal variations (increases in incidence of cervical rib and extra sternebral ossification sites) were seen at 100 mg/kg/day. In a perinatal and postnatal toxicity study in rats, this drug (administered orally) prolonged duration of gestation and labor and produced dystocia with related increases in maternal mortality and decreases in perinatal survival of pups at 10 mg/kg/day (about 0.3 times the RHD). There are no controlled data in human pregnancy.

AU TGA pregnancy category B3: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have shown evidence of an increased occurrence of fetal damage, the significance of which is considered uncertain in humans.

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

Breastfeeding must be stopped on initiation of therapy.

Excreted into human milk: Unknown
Excreted into animal milk: Unknown

Comments:
-Developmental and health benefits of breastfeeding should be considered as well as the mother's clinical need for this drug.
-The effects in the nursing infant are unknown; potential side effects in the breastfed child due to this drug or the mother's underlying condition should be considered.

See references