Interferon-beta exposure during first trimester is safe in women with multiple sclerosisA prospective cohort study from the German Multiple Sclerosis and Pregnancy Registry

Background: Available data suggest that pregnancy exposure to interferon-beta might result in lower mean birth weight and preterm birth. Objective: To determine the effect of interferon-beta exposure during pregnancy on pregnancy outcomes in multiple sclerosis patients. Methods: We compared the pregnancy outcomes of women exposed to interferon-beta with pregnancies unexposed to disease-modifying therapies. Women were enrolled into the German Multiple Sclerosis and Pregnancy Registry. A standardized questionnaire was administered during pregnancy and postpartum. Detailed information on course of multiple sclerosis and pregnancy, concomitant medications, delivery, and outcome of pregnancy was obtained. Results: We collected data on 251 pregnancies exposed to interferon-beta and 194 unexposed to disease-modifying therapies. In all, 246 (98.01%) women discontinued interferon-beta treatment during first trimester. No differences regarding mean birth weight (exposed: 3272.28563.61 g; unexposed: 3267.46 +/- 609.81g), mean birth length (exposed: 50.73 +/- 3.30cm; unexposed: 50.88 +/- 3.45cm), preterm birth (p=0.187), spontaneous abortion (p=0.304), and congenital anomalies (p=0.197) were observed between the two groups. Conclusions: Interferon-beta exposure during early pregnancy does not influence the mean birth weight, risk of preterm birth, or other adverse pregnancy outcomes. Our study provides further reassurance that interferon-beta treatment can be safely continued up until women become pregnant.