Use of a ribavirin-containing regimen is contraindicated in pregnant women and in the male partners of women who are pregnant; simeprevir should be used in women who are or may become pregnant only if the benefit outweighs the risk.

For regimens containing ribavirin and peginterferon alfa:
-AU TGA pregnancy category: X

For simeprevir:
-AU TGA pregnancy category: B3
-US FDA pregnancy category: Not assigned.

Risk summary: No data available on use of this drug in pregnant women to inform a drug-related risk; findings in animal studies suggest potential risk to the fetus.

Comments:
-If this drug is used during pregnancy, the patient should be apprised of the potential harm to the fetus.
-According to some authorities: Effective contraception is required for women of childbearing potential using this drug.
-The manufacturer product information for coadministered hepatitis C virus (HCV) antiviral drugs should be consulted regarding use during pregnancy and use in females and males of reproductive potential.
-Effective contraception is required during ribavirin therapy and for 6 months after the last dose; local protocol should be consulted regarding contraception timing.

Animal studies have revealed evidence of fetal harm; embryofetal developmental toxicity was seen at drug exposures higher than human exposure at the recommended clinical dose. In mice, significantly reduced fetal weights, increased fetal skeletal variations (e.g., supernumerary ribs, delayed ossification), early and late in utero fetal losses, and early maternal deaths were seen with exposures about 4 or 6 times higher than the AUC in humans at the recommended daily dose. In pregnant rats, early deaths and significantly reduced body weight gain were seen at exposures similar to and 0.7 times the AUC in humans at the recommended daily dose, respectively. Significantly reduced body weight and negative effects on physical growth (delay and small size) and development (decreased motor activity) were seen in developing rat offspring exposed to this drug in utero; maternal exposure was similar to the AUC in humans at the recommended daily dose. There are no controlled data in human pregnancy. This drug must be used with other HCV antiviral drugs.

Pregnancy must be avoided in female patients and female partners of male patients using a ribavirin-containing regimen. All animal species exposed to ribavirin have shown significant teratogenic and/or embryocidal effects. Females of reproductive potential and their male partners should not receive ribavirin unless they are using effective contraception during therapy and for 6 months after therapy.

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.

AU TGA pregnancy category X: Drugs which have such a high risk of causing permanent damage to the fetus that they should not be used in pregnancy or when there is a possibility of pregnancy.

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

LactMed: If the mother requires this drug, it is not a reason to discontinue breastfeeding; some experts recommend against breastfeeding when this drug is used with ribavirin.
-According to some authorities: 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: Unknown
Excreted into animal milk: Yes

Comments:
-This drug has not been studied in nursing mothers receiving treatment for hepatitis C virus infection.
-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.
-The manufacturer product information for coadministered hepatitis C virus antiviral drugs (especially ribavirin and peginterferon alfa) should be consulted.

See references