#AANAM – Interferon Beta Exposure Does Not Seem to Increase Risk of Pregnancy Complications, Study Suggests

Exposure to interferon beta does not seem to increase the risk of complications during pregnancy in women with multiple sclerosis (MS), new research suggests.

The data were presented in an oral presentation, “Pregnancy and Infant Outcomes with Interferon Beta: Data from the European Interferon Beta Pregnancy Registry and MS Preg study conducted in Finland and Sweden,” by Kerstin Hellwig, MD, an MS specialist in the department of neurology at St. Josef Hospital/Ruhr University, in Germany. Hellwig made her presentation at the 2019 Annual Meeting of the American Academy of Neurology, which took place May 4–10 in Philadelphia.

Women with MS often are diagnosed with the disease at a childbearing age. Therefore, the choice of treatment plan is cruical, as well as a better understanding of MS treatment effects on pregnancy and infant outcomes, so that risks can be mitigated.

Interferon beta is commonly used to treat MS, and previous studies suggest that taking it during pregnancy is safe, but limited data is available.

To address this, researchers analyzed data from European registries, and of patients in Nordic health registers in Finland and Sweden. According to Hellwig, these registries “are the largest cohort studies providing safety data of women with MS of child-bearing age exposed to interferon beta.”

Researchers identified 1,823 pregnancies in women with MS (948 in the European registry, and 875 in the Nordic registers) who had been exposed to interferon beta — defined as using the treatment during pregnancy, or in the three months immediately prior to pregnancy.

Reported outcomes of these pregnancies were compared with those in MS patients who were not receiving treatment before or during their pregnancy.

Results showed that the rates of spontaneous abortions and congenital abnormalities were similar in the patients, regardless of whether or not they received interferon beta treatment.

Spontaneous abortions were reported in 10.7% of the European cohort, 7.9% in the Nordic cohort, and 11.1% in the non-treated group. Congenital abnormalities were detected in 1.8% of both the European and Nordic cohorts, and in 3.3% of the cohort not receiving interferon beta.

The rates of ectopic pregnancy — a condition where a fetus starts to grow outside of the uterus — were also similar (0.4%, 1.5%, and 2.9% in each cohort, respectively).

Importantly, the rates of complications seen in the study are in line with the rates from the general population.

Taken together, “based on the European and Nordic studies, no evidence of IFNβ [interferon beta] exposure before conception and/or during the first trimester of pregnancy adversely affected pregnancy or infant outcomes,” Hellwig concluded.

Interferon beta-based therapies approved for MS treatment include EMD Serono’s Rebif, Biogen’s Plegridy and Avonex, Bayer’s Betaseron/Betaferon, and Novartis’ Extavia.