Benefit should outweigh risk

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

Risk Summary: There are no adequate and well-controlled studies in pregnant women; in animals, an increased incidence of fetal malformations has been associated with carbidopa-levodopa or entacapone administration throughout organogenesis.

In rabbit studies, all tested doses and ratios of carbidopa-levodopa showed an increased incidence of visceral and skeletal malformations (doses up to 20 times [carbidopa] and 10 times [levodopa] the maximum recommended human dose [MRHD]). In rats, there was a decrease in the number of live pups delivered by dams receiving 2 (carbidopa) to 5 (levodopa) times the MRHD throughout organogenesis. Entacapone administration to female rats prior to mating and during early gestation at doses of 160 mg/kg/day (7 times the MRHD) produced an increased incidence of fetal eye anomalies (macrophthalmia, microphthalmia, anophthalmia). Levodopa appears to cross the human placental barrier and be metabolized by the fetus; carbidopa concentrations in fetal tissue appear to be minimal. There are no adequate or well controlled studies from the use of combination levodopa/carbidopa/entacapone in pregnant women.

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.

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Carbidopa and entacapone are excreted in rat milk; levodopa is excreted in human breast milk. Oral administration of entacapone to rats from early pregnancy to weaning reduced offspring bodyweight at maternal doses producing an AUC of 26 times the maximal clinical exposure, but not with exposure of 6 times the maximal clinical exposure. Limited data exists on levodopa's effect on milk production, although several studies have shown it decreases serum prolactin during lactation. The prolactin level in a mother with established lactation may not affect her ability to breastfeed. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for this drug and any potential adverse effects to the breastfed infant from the drug or from the underlying maternal condition. Some authorities recommend against use as the safety is not known in the breastfed infant.

Benefit should outweigh risk

Excreted into human milk: Yes (levodopa)
Excreted into animal milk: Yes (carbidopa, entacapone)

Comments: The effects in the nursing infant are unknown.

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