This drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.

AU TGA pregnancy category: B1
US FDA pregnancy category: B

Comments:
-Exposure to this drug in the second and/or third trimester of pregnancy has been shown to reduce risk of mother-to-infant hepatitis B virus (HBV) transmission if this drug is given to the mother and hepatitis B immune globulin and HBV vaccine are administered to the newborn (on day of birth).

Animal studies have failed to reveal evidence of teratogenicity, embryofetal toxicity, or fetal harm; in pregnant rabbits at plasma levels 37 times higher than levels in humans at therapeutic dose, early deliveries and/or abortions were observed resulting from maternal toxicity (body weight loss). Animal studies have shown that this drug crosses the placenta. There are no controlled data in human pregnancy.

To monitor fetal outcomes of pregnant women exposed to this drug, a pregnancy registry has been established. Healthcare providers are encouraged to prospectively register patients. For additional information: apregistry.com

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 B: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.

See references

LactMed: An alternative agent may be preferred, particularly while breastfeeding newborn or preterm infants.
-According to some authorities: Breastfeeding is not recommended during use of this drug.

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

Comments:
-This drug has not been studied in nursing mothers receiving treatment for hepatitis B virus infection.

See references