Animal studies have failed to reveal evidence of embryofetal toxicity or teratogenicity. No adverse embryofetal effects were seen after oral doses resulting in systemic exposures (AUC) about 5 and 7 times (rats and rabbits, respectively) the systemic drug exposure at the maximum recommended human dose; in rabbits administered 1000 mg/kg/day (a maternally toxic dose), fetal skeletal variations occurred and resulted in 2 abortions out of 19 pregnancies. A tissue distribution study in pregnant rats showed this drug crosses the placenta. There are no controlled data in human pregnancy.

Pregnant women have higher risk of severe complications from influenza, which may lead to adverse pregnancy and/or fetal outcomes.

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.

According to some authorities: Use should be avoided during pregnancy unless the benefit outweighs the risk to the fetus.
According to some authorities: As a precaution, use should preferably be avoided.

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.

Comments:
-Risks to mother and fetus associated with influenza during pregnancy should be considered.

See references

LactMed: An alternative agent may be preferred, especially while breastfeeding newborn or preterm infants.
-According to some authorities: A decision should be made to discontinue breastfeeding or to start treatment with the drug, taking into account the potential benefit of the drug to the mother and the potential risk to the infant.

Excreted into human milk: Unknown
Excreted into animal milk: Yes (drug and its metabolites)

Comments:
-No data available on the use of this drug during breastfeeding.
-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.

Because this drug is 93% bound to plasma proteins, the amount in milk is likely to be low.

See references