To review pregnancy outcomes of patients who are exposed to interferon beta-1b during pregnancy.

Multiple Sclerosis predominantly affects women of fertile age. Thus information on drug exposure during pregnancy is crucial. Randomized trials are not possible. Therefore pharmacovigilance safety data can provide crucial data sets for decision making around family planning while on treatment.

Pregnancy cases with exposure to interferon beta-1b reported prospectively up to February 2018 were retrieved from Bayer HealthCare’s pharmacovigilance database. Congenital malformations were classified according to ICD-10. Pregnancy outcomes were compared with reference rates of abnormal pregnancy outcomes from the general population.

As of February 2018, 2571 pregnancies exposed to interferon beta-1b from 2537 individual case safety reports were retrieved. A total of 1351 pregnancies had documented outcomes. The majority of the outcomes were normal live births (66.3 %). The rates of congenital malformations (1.6 %) and spontaneous abortions (11.8 %) were comparable to the estimated rates for the general population worldwide.

This is the largest sample of exposure to interferon beta-1b during pregnancy.  Pregnancies exposed to interferon beta-1b were not at a higher risk for spontaneous abortion or congenital anomalies when compared with the expected rates in the general population.