Animal studies have failed to reveal evidence of fetal harm. There are no controlled data in human pregnancy.

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 B1: 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 not shown evidence of an increased occurrence of fetal damage.

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.

Combination therapy: Use of a ribavirin-containing regimen is contraindicated in pregnant women and in the male partners of women who are pregnant.
Monotherapy: This drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.
-According to some authorities: As a precaution, use is not recommended.

For combination therapy:
-AU TGA pregnancy category: X

For monotherapy:
-AU TGA pregnancy category: B1
-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.

Comments:
-If applicable, the manufacturer product information for ribavirin 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.

See references

LactMed: Some experts recommend against breastfeeding when this drug is used with ribavirin.
-According to some authorities: Use is not recommended.

Excreted into human milk: Unknown
Excreted into animal milk: Yes (GS-331007 [main circulating metabolite of sofosbuvir], velpatasvir)

Comments:
-The 2 active components have not been studied in nursing mothers receiving treatment for hepatitis C virus (HCV) 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 ribavirin should be consulted (if applicable).
-According to the US CDC, mothers with HCV infection should not breastfeed if their nipples are cracked/bleeding; unclear if this warning applies to nursing mothers receiving treatment for HCV infection.

Amounts of velpatasvir in breast milk are most likely very low as it is highly bound to maternal plasma proteins.

See references