Pregnancy outcomes after exposure to interferon beta: a register-based cohort study among women with MS in Finland and Sweden.

BACKGROUND

Our aim was to estimate and compare the prevalence of adverse pregnancy outcomes among pregnant women with multiple sclerosis (MS) exposed to interferon beta (IFNB) and among women with MS unexposed to any MS disease-modifying drug (MSDMD).

METHODS

This cohort study used Finnish (1996-2014) and Swedish (2005-2014) national register data. Women with MS having IFNB dispensed 6 months before or during pregnancy as the only medication were considered as IFNB exposed (only IFNB-exposed), whereas women with MS unexposed to any MSDMD were considered unexposed (MSDMD-unexposed). Prevalence was described and compared using log-binomial or logistic regression and adjusted for potential confounders including maternal age and comorbidity.

RESULTS

Among 2831 pregnancies, 2.2% of the only IFNB-exposed and 4.0% of the MSDMD-unexposed women had serious adverse pregnancy outcomes [elective termination of pregnancy due to foetal anomaly (TOPFA), major congenital anomaly (MCA) in live, or stillbirth]. After adjustments, the prevalence of serious adverse pregnancy outcomes was lower among the only IFNB-exposed compared with the MSDMD-unexposed [relative risk 0.55, 95% confidence interval (CI) 0.31-0.96]. The prevalence of individual outcomes, including MCA, spontaneous abortions, and stillbirths was not increased with IFNB exposure. Women with MS exposed to IFNB appeared more likely to terminate their pregnancy for reasons other than foetal anomaly, compared with MSDMD-unexposed pregnant MS patients (odds ratio 1.71, 95% CI 1.06-2.78).

CONCLUSION

In this large cohort study, no increase in the prevalence of adverse pregnancy outcomes was observed in women with MS exposed to IFNB compared with MS patients unexposed to any MSDMDs. This study together with other evidence led to a change in the labels of the IFNB products in September 2019 in the European Union, and IFNB use today may be considered during pregnancy, if clinically needed.

Informations de copyright

© The Author(s), 2020.

Déclaration de conflit d'intérêts

Conflict of interest statement: Katja Hakkarainen is an employee of StatFinn & EPID Research which performs commissioned pharmacoepidemiological studies for several pharmaceutical companies. Rosa Juuti was at the time of conducting the study an employee of StatFinn & EPID Research which performs commissioned pharmacoepidemiological studies for several pharmaceutical companies. Sarah Burkill was at the time of conducting the study an employee at the Centre for Pharmacoepidemiology, which receive grants from several entities including pharmaceutical companies. Yvonne Geissbühler is an employee of Novartis Pharma AG. Meritxell Sabidó is an employee of Merck KGaA, Darmstadt, Germany. Catrinel Popescu is an employee and stockholder of Biogen. Kiliana Suzart-Woischnik is an employee of Bayer AG. Jan Hillert received unrestricted grants, honoraria for serving on advisory boards and/or speaker honoraria from Biogen, Sanofi-Genzyme, Novartis, Merck-Serono, Bayer-Schering, Teva and Biogen Idec. This MS research was funded by the Swedish Research Council and the Swedish Brain foundation. Miia Artama reports no disclosures. Auli Verkkoniemi-Ahola received investigator fees (Sanofi) and congress fee covering or honoraria for lectures or advisory boards (Biogen, Merck, Novartis, Roche, Sanofi-Genzyme, Grifols). Kjell-Morten Myhr received unrestricted grants and/or speaker honoraria and/or scientific advisory board honoraria from Almirall, Biogen, Genzyme, Merck, Novartis, Sanofi-Aventis, Roche and the Norwegian MS Society. Juha Mehtälä was at the time of conducting the study an employee of StatFinn & EPID Research which performs commissioned pharmacoepidemiological studies for several pharmaceutical companies. Shahram Bahmanyar is an employee at the Centre for Pharmacoepidemiology, which receives grants from several entities including pharmaceutical companies. Scott Montgomery received funding for MS research in the last 5 years from Roche, Novartis and AstraZeneca; and speaker’s honoraria, including from Teva. Pasi Korhonen was at the time of conducting the study an employee of StatFinn & EPID Research which performs commissioned pharmacoepidemiological studies for several pharmaceutical companies.