Animal studies with glecaprevir have failed to reveal evidence of embryofetal toxicity in rats (exposures up to 53 times the exposure in humans at the recommended human dose [RHD]); in rabbits, maternal toxicity (anorexia, lower body weight, lower body weight gain) with some embryofetal toxicity (increased postimplantation loss, increased number of resorptions, decreased fetal body weight) prevented evaluation of glecaprevir at clinical exposures (highest exposure reached in rabbits was 0.07 times the exposure in humans at RHD). Animal studies with pibrentasvir have failed to reveal evidence of embryofetal toxicity in mice and rabbits (exposures up to 51 and 1.5 times the exposure in humans at RHD, respectively). Glecaprevir and pibrentasvir have been shown to cross the placenta in rats and in mice and rabbits, respectively. There are no controlled data in human pregnancy.

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.

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.

According to some authorities: As a precaution, use is not recommended.

AU TGA pregnancy category: B1
US FDA pregnancy category: Not assigned.

Risk summary: No adequate data available on use of this drug in pregnant women to inform a drug-related risk.

See references

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 and the benefit of breastfeeding for the child.

Excreted into human milk: Unknown
Excreted into animal milk: Yes (both components)

Comments:
-The 2 active components have 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.

Amounts of each component in breast milk are most likely very low as both components are highly bound to maternal plasma proteins.

See references