An Observational Study to Learn About the Interferon-beta Exposure of Pregnant Women During the Second and Third Trimester in Finland and Sweden

Observational data have suggested no increased risk of adverse pregnancy outcomes associated with exposure to interferon-beta (IFNB) before or during pregnancy. After the emergence of these data, the European Medicines Agency approved a label change for IFNB in September 2019, stating that use of IFNB during pregnancy may be considered, if clinically needed. However, limited data on pregnancies exposed in the 2nd and 3rd trimesters were observed. INFORM is a secondary use of data drug utilisation study (DUS) to determine late pregnancy exposure (i.e. during the 2nd and 3rd trimester) to IFNB in Finland and Sweden, which will inform whether the number of exposed pregnancies is adequate to conduct a cohort study on adverse pregnancy outcomes, with a focus on late pregnancy exposure. The number of pregnancies will be initially reported three years after the revised label implementation (September 2019) and will include data on pregnancies from 1996 in Finland and from 2005 in Sweden up through 31 December 2022. If the number of pregnancies is deemed adequate for conducting the cohort study on adverse pregnancy outcomes, this DUS will be finalised with the drug utilisation data accrued up through 31 December 2022. If the number of pregnancies until 31 December 2022 is deemed inadequate, this study may be continued and the primary and secondary objectives may be examined five years after the revised label implementation, including pregnancies until 31 December 2024.