LAUSR

Background: The goal of the present cohort study was to review outcomes of patients exposed to interferon beta-1b during pregnancy. Methods: Pregnancy cases with exposure to interferon beta-1b reported to Bayer’s pharmacovigilance (PV) database from worldwide sources from January 1995 through February 2018 were retrieved for evaluation. Only cases where pregnancy outcomes were unknown at the time of reporting (i.e. prospective cases) were included in the analysis of this retrospective cohort study. Results: As of February 2018, 2581 prospective pregnancies exposed to interferon beta-1b were retrieved from the database; 1348 pregnancies had documented outcomes. The majority of outcomes [1106 cases (82.0%)] were live births. Health status was known for 981 live births (no known health status for 125). Most of the prospective pregnancies with known outcomes corresponded to live births with no congenital anomalies [896 cases (91.3%)]. Spontaneous abortion occurred in 160 cases (11.9%). Congenital birth defects were observed in 14/981 live births with known health status [1.4%, 95% confidence interval (CI) 0.78–2.38]. No consistent pattern in the type of birth defect was identified. Rates of both spontaneous abortion and birth defects were not higher than the general population. Conclusions: These PV data, the largest sample of interferon beta-1b-exposed patients reported to date, suggest no increase in risk of spontaneous abortion or congenital anomalies in women exposed during pregnancy.