Animal studies revealed embryo fetal toxicity including reduced fetal viability, skeletal delays, and multiple malformations at doses equivalent to and less than the maximum recommended human dose (MRHD). Embryofetal toxicity may have been secondary to the significant maternal toxicity also observed in the study. Opioid analgesics cross the placenta. The use of this drug during labor may cause respiratory depression in the newborn infant. Prolonged use of opioids during pregnancy can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth There are no controlled data in human pregnancy.

AU TGA pregnancy category C: Drugs which, owing to their pharmacological effects, have caused or may be suspected of causing, harmful effects on the human fetus or neonate without causing malformations. These effects may be reversible. Accompanying texts should be consulted for further details.

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.

Benefit should outweigh risk

AU TGA pregnancy category: C
US FDA pregnancy category: Not assigned

Risk Summary: Based on animal data, may cause fetal harm; prolonged use of opioids during pregnancy can result in physical dependence in the neonate.

Comments:
-Women using opioids during pregnancy for medical or nonmedical purposes should be advised of the risk of neonatal abstinence syndrome and ensure that appropriate treatment will be available.
-Long-acting opioids should not be used during and immediately prior to labor, when short acting analgesics or other analgesic techniques are more appropriate.

See references

Use is not recommended and 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: Withdrawal symptoms can occur in breast-feeding infants when maternal administration of this drug is stopped.

Animal studies during lactation, at doses lower than those associated with maternal toxicity, resulted in increased postnatal pup mortality.

See references