Animal studies revealed evidence of embryotoxicity and teratogenicity. There are no controlled data in human pregnancy.

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 C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

AU: Use of ketoconazole is contraindicated; it is not recommended unless clearly needed and the benefit outweighs the risk.
UK: Use of ketoconazole is contraindicated.
US: Ketoconazole should be used during pregnancy only if the benefit outweighs the risk to the fetus.

AU TGA pregnancy category: B3
US FDA pregnancy category: C

See references

A nursing woman was treated with ketoconazole 200 mg orally once a day. Based on samples measured after the tenth dose, it was estimated that the infant received a maximum daily dosage that was 1.4% of the mother's weight-adjusted dosage. The mother continued to breastfeed the infant during therapy. No adverse effects were reported in the infant.

Breastfeeding is not recommended during use of ketoconazole.

Excreted into human milk: Yes

The effects in the nursing infant are unknown.

See references