Does pregnancy affect women with multiple sclerosis? A prospective study in Western China

Objectives: Pregnancy is considered to be protective for multiple sclerosis (MS) but little is known about Asian MS women. Our study aimed to investigate whether pregnancy affects the course of MS and whether MS affects pregnancy in a Chinese cohort. Methods: We established a database (2009-2016) of 94 females with MS in the Department of Neurology at West China Hospital. From this database, we enrolled females who had been pregnant before or after the clinical onset of MS and consecutively followed up the patients and their offspring for at least one year after delivery. We registered their demographic, clinical and pregnancy-related information, as well as the annualized relapse rate (ARR) and Expanded Disability Status Scale (EDSS) score. Results: We enrolled 55 females with MS and 126 pregnancies. Among them, 14 females had 15 deliveries after MS onset. In these 15 full-term pregnancies after MS onset, the average ARR decreased from 0.46 +/- 0.52 in the year before pregnancy to 0.07 +/- 0.26 (P = .034) during pregnancy and no drug exposure were observed during pregnancy. The average EDSS score at one year after delivery (1.50 +/- 1.72) was higher than that at conception (0.77 +/- 1.35; P = .045). Conclusions: The natural history of MS during pregnancy suggests that full-term pregnancy protects MS females from relapse. However, the disability of MS females may develop after delivery.