Fetal Risk Summary
Leuprolide is a synthetic nonapeptide analogue of naturally occurring gonadotropin-releasing hormone that inhibits the secretion of gonadotropin when given continuously and in therapeutic doses.
Leuprolide causes a dose-related increase in the incidence of major malformations in pregnant rabbits, but not in rats (1). The most frequently observed malformations in rabbits were vertebral anomalies and hydrocephalus (J.D. Miller, personal communication, Tap Pharmaceuticals, Inc., 1992). The doses tested were 1/3001/3 of the typical human dose. Increased fetal mortality and decreased fetal weights were observed in both animal species with the higher test doses.
In humans, spontaneous abortions or intrauterine growth retardation are theoretically possible because leuprolide suppresses endometrial proliferation. The risk of these adverse outcomes is considered greater than the risk of congenital malformations because the affected organs in animal studies do not depend on the presence of gonadal steroids for normal development (J.D. Miller, personal communication, Tap Pharmaceuticals, Inc., 1992).
The manufacturer is maintaining a registry of inadvertent human exposures during pregnancy to leuprolide and currently has more than 100 such cases (J.D. Miller, personal communication, Tap Pharmaceuticals, Inc., 1992). No cases of congenital defects attributable to the drug have been reported, although the numbers are too small to draw conclusions as to the risk for perinatal mortality, low birth weight, or teratogenicity.
Breast Feeding Summary
No data are available.
- Product information. Lupron. Tap Pharmaceuticals, Inc., 1990.