Exposure to interferon-beta in early pregnancy has no influence on birth weight, risk of preterm birth, or other adverse pregnancy outcomes, according to a prospective cohort study conducted in Germany.
The results should be considered a relief for women with multiple sclerosis, as previous data suggested that pregnancy exposure to interferon-beta might result in pregnancy and birth complications.
In the current study, Sandra Thiel, of St. Josef Hospital, Ruhr University Bochum in Bochum, Germany, and colleagues compared pregnancy outcomes in women exposed to interferon-beta and those not exposed to disease-modifying therapies.
Participants completed a questionnaire during pregnancy and postpartum that included information on multiple sclerosis and pregnancy, concomitant medications, delivery, and pregnancy outcomes.
In total, 445 pregnancies in women with multiple sclerosis were included in the study, including 251 pregnancies exposed to interferon-beta and 194 unexposed. Over 98% (n=246) of women discontinued treatment with interferon-beta in the first trimester, with a median duration of exposure of 32 days. Of the 194 unexposed pregnancies in the control group, over 70% of women were treated with a disease-modifying therapy at some point prior to pregnancy, but had stopped prior to pregnancy. In total, 89 women experienced 1 or more relapses during pregnancy; 16 experienced 2; and 3 experienced 3 relapses. Women who were not taking interferon-beta at time of pregnancy experienced significantly more relapses than those with early pregnancy exposure to interferon-beta.