No reports describing the use of interferon gamma-1b in human pregnancy have been located. Interferon gamma-1b, produced by recombinant DNA technology, is used to reduce the frequency and severity of serious infections in patients who have chronic granulomatous disease (1). Because of this indication, the opportunities for its use in human pregnancy should be rare.
Interferon Gamma-1B (Actimmune)
Pregnancy Recommendation:No Human Data—Animal Data Suggest Low Risk
Breastfeeding Recommendation:No Human Data—Probably Compatible
Interferon gamma-1b has abortifacient activity in nonhuman primates treated with a dose approximately 100 times the human dose (HD) (1). Similar activity was observed in mice treated with maternally toxic doses. Other effects noted in mice were an increased incidence of uterine bleeding and decreased neonatal viability (1). However, no evidence of teratogenicity was found in primates with doses of 2-100 times the HD (1).
Animal Data: Treatment of pregnant mice with 5000 units/day for 6 days produced maternal and fetal hematologic toxicity (2). In addition to an increase in aborted fetuses and decreased fetal weight, severe anomalies, consisting of inhibition or retardation of eye formation and brain hematomas, were observed in surviving fetuses (2).
Two reviews have summarized the effects and actions of endogenous interferons (alpha, beta, and gamma) in animal and human pregnancies and the presence of these proteins in various maternal and fetal tissues (3,4).