The majority of individuals obtaining the diagnosis of multiple sclerosis are women of childbearing age. They are naturally concerned as to how multiple sclerosis affects the course of pregnancy and the developing foetus. The objective of this study was to prospectively evaluate the incidence of pregnancy complications and delivery risks, and to follow the natural course of multiple sclerosis during and after pregnancy in a cohort of Finnish patients with multiple sclerosis. Sixty-one patients with multiple sclerosis who became pregnant during the years 2003-2005 were prospectively followed-up from early pregnancy until 6 months postpartum. Multiple sclerosis relapses, Expanded Disability Status Scale rates and obstetric details were recorded. The results were compared with the statistics obtained from Finnish Medical Birth Register from the year 2004. We found that patients with multiple sclerosis were no more likely to experience pregnancy complications than Finnish pregnant women generally, but they had a greater likelihood for a need of artificial insemination (4.9% vs. 0.9%; p = 0.0009). Subjects with multiple sclerosis were more likely to undergo assisted vaginal delivery than the at-large cohort (16.4% vs. 6.5%; p = 0.0017). We conclude that pregnancy does not seem to pose a woman with multiple sclerosis to a greater risk for pregnancy complications when compared with women in general. The potential need for instrumental delivery should, however, be taken into account when planning the delivery of a mother with multiple sclerosis.