The primary objectives of the study are to estimate the risk of major congenital malformations (MCMs) in infants born to women with multiple sclerosis (MS) who were exposed to diroximel fumarate (DRF) at any time from 2 weeks after the first day of their last menstrual period (LMP) up through the first trimester of pregnancy and to comparatively evaluate pregnancy outcomes with MCMs in women with MS who were exposed to DRF at any time from 2 weeks after the first day of their LMP through the first trimester of pregnancy with the following: i) women with MS who were unexposed to disease modifying therapies (DMTs) and, ii) women with MS who were exposed to other DMTs (e.g., Avonex and Tysabri Pregnancy Registries). The secondary objective of the study is to evaluate pregnancy outcomes in women with DRF exposure at any time from 2 weeks after the first day of their LMP through the end of pregnancy compared with the following: i) women with MS who were unexposed to DMTs, ii) women with dimethyl fumarate (DMF) exposure, iii) women with MS who were exposed to other DMTs (e.g., Avonex and Tysabri Pregnancy Registries), and iv) women without MS (e.g., women from external, general population comparators).