Benefit should outweigh risk.

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

Risk summary: There are no studies with topical or oral oxybutynin use in pregnant women to inform any drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes.

Studies in animals have shown minor reproductive toxicity. There are no controlled data in human pregnancy. It is not known whether this drug can cause fetal harm or adversely affect reproductive capacity in humans.

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.

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In postmarketing surveillance, cases of lactation suppression have been reported with the use of this drug.

Benefit should outweigh risk.
-According to some authorities: Use is not recommended.

Excreted into human milk: Yes (in small amounts)
Excreted into animal milk: Yes

Comments:
-The effects in the nursing infant are unknown.
-Long-term use of this drug might reduce milk production or milk letdown, but a single dose is not likely to interfere with breastfeeding.
-During long-term use, observe for signs of decreased lactation (e.g., insatiety, poor weight gain).

See references