BERLIN—European registry data do not support the hypothesis that exposure to interferon beta before conception or during pregnancy adversely affects pregnancy outcome or infant outcome, according to an analysis presented at ECTRIMS 2018.
In women, diagnosis of multiple sclerosis (MS) and treatment initiation often occur during childbearing years, but neurologists have not reached consensus about treatment before or during pregnancy. The European Interferon Beta Pregnancy Registry was created to gather evidence about the effect of this treatment on maternal and fetal outcomes. A separate population-based cohort study examined health care registry data from Finland and Sweden (ie, Nordic registries) for the same purpose.
An Analysis of Prospective Data
Kerstin Hellwig, MD, Senior Consultant Neurologist and researcher at St. Joseph and St. Elizabeth Hospital and Ruhr University in Bochum, Germany, and colleagues examined these databases to evaluate the prevalence of pregnancy and infant outcomes in women with MS who had been exposed to interferon beta. The investigators analyzed 948 pregnancy reports with recorded pregnancy outcomes from the European Interferon Beta Pregnancy Registry. They also examined 875 pregnancy events in the Nordic registries among patients exposed to interferon beta and other treatments and 1,831 events among untreated patients.
Treatment Did Not Affect Birth Weight
Approximately 82% of pregnancies in the European registry had an outcome of live birth without congenital anomalies. The prevalence of spontaneous abortions and live births with congenital anomalies were similar to those reported in the general population.
About 98% of pregnancies in the exposed cohort of the Nordic registries had an outcome of live birth without congenital anomalies. This result is similar to the corresponding 97% rate in the nonexposed cohort. The prevalence of spontaneous abortions and congenital anomalies also were similar between the exposed and nonexposed cohorts of the Nordic registries.
Birth weights ranged from 580 g to 5,160 g in the Nordic registries. The proportion of babies with low or very low birth weight was 5.0% in the interferon-exposed cohort, 4.7% among babies exposed to interferon and other treatments, and 5.8% among nonexposed babies. Mean birth weight was 3,421.2 g in the interferon-exposed cohort, 3,434.3 g in the cohort exposed to interferon and other treatments, and 3,389.3 g in the nonexposed cohort. These weights were consistent with results from the prospective German pregnancy registry, according to the authors. Birth weights were not recorded systematically in the European registry.
“The European Interferon Beta Pregnancy Registry showed no evidence that interferon beta exposure before conception or during pregnancy adversely affected pregnancy or infant outcomes,” said Dr. Hellwig and colleagues. “This is consistent with data collected from the Nordic registers.”
This study was supported by Merck in Darmstadt, Germany. Additional funding for analysis, project management, and medical writing was provided by Bayer, Biogen, Merck, and Novartis Pharma.
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