Animal studies have revealed evidence of harmful effects, and there is a possibility of teratogenic effects in humans. There are no controlled data in human pregnancy.

Male animal models have revealed evidence of spermatocyte and sperm aberrations. There are no controlled data in human males.

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.

Use is recommended only if clearly needed and the benefit outweighs the risk to the fetus.

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

Risk Summary: The malformative risk with use of this drug in pregnant women is unknown. Patients have reported teratogenic effects; extrapyramidal and withdrawal symptoms have been reported in exposed neonates.

Comments:
-The dose and duration of treatment in pregnant patients should be as low and short as possible.
-Neonates exposed during the third trimester are at risk of developing severe and/or prolonged side effects (e.g., agitation, hyper/hypotonia, tremor, somnolence, respiratory distress, feeding disorder, low Apgar score). The side effects have varied in severity and duration, with some neonates requiring intensive care support and prolonged hospitalization.
-If used during labor, this drug should be withheld until the cervix is dilated 3 to 4 cm.
-Exposed neonates should be monitored for the signs/symptoms of extrapyramidal syndrome and/or withdrawal.

See references

Use is not recommended unless clearly needed and the benefit outweighs the risk.

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

Comments:
-Some experts state that use is contraindicated. The manufacturer product information and local protocol should be consulted regarding use during lactation.
-The effects in the nursing infant are unknown.

Other phenothiazines (e.g., chlorpromazine) have been detected in human breastmilk.

See references