BACKGROUND: The age of multiple sclerosis (MS) onset coincides with fertile age, and both improved prognosis and treatment may influence birth rates in people with MS (pwMS). OBJECTIVES: To investigate birth rates over time in pwMS compared with controls. METHODS: This cohort study included pwMS from three hospitals in the southeast of Norway. Clinical data were collected prospectively. Statistics Norway provided year of live births and marital status in pwMS and controls matched for age, sex, and place of residence at age 16. RESULTS: We included 1599 pwMS (1118 women with MS (wMS) and 481 men with MS (mMS)) and 23,855 controls. The mean number of live births was 1.5 (standard deviation (SD) 1.2) for pwMS versus 1.8 (SD 1.2) for controls ( CONCLUSION: wMS have reduced rates of childbirth compared with controls. This is significant already in the prodromal phase.