Outcomes of Pregnancy in Egyptian Women with Multiple Sclerosis in the New Treatment Era: A Multi-Center Retrospective Observational Study.

Background Pregnancy is a recent growing issue in multiple sclerosis (MS) and the update in the diagnostic criteria of MS and introduction of many disease-modifying therapies (DMTs) may cause changes in the relationship between MS, pregnancy, and breastfeeding. This study aimed to investigate the effect of pregnancy and breastfeeding on MS and vice versa. A retrospective observational study was conducted to include MS women with a history of at least one pregnancy during the last 7 years. Data were collected from the archived files in addition to a self-administrating questionnaire. The annualized relapsing rate (ARR) was calculated before, during, and after pregnancy. Results We included 116 successful pregnancies from 93 MS women with mean age 32.74 ± 5.12 years. Interferon-beta was the commonly used DMT during and after pregnancy. Despite the ARR during the two years preceding the conception was 0.36 (95% CI 0.32–0.41), this rate was significantly decreased during first, second, and third trimester (0.07; 95% CI 0.04–0.15, 0.10; 95% CI 0.03–0.17, and 0.15; 95% CI 0.08–0.24, respectively; P -value < 0.001 in all). Furthermore, this ARR was significantly decreased during the first and last three months after delivery (0.27; 95% CI 0.16–0.39; P -value = 0.037, and 0.24; 95% CI 0.17–0.38; P -value = 0.023). Exclusive breastfeeding was associated with deceased risk of postpartum relapse, with HR 0.31 (95% CI 0.12–0.67; P = 0.002). Conclusions Pregnancy is protective from MS relapse, with a significant decrease of ARR from the pre-pregnancy period. Postpartum reactivation of the disease occurs from the third month after labor, rather than the early postpartum period. Exclusive breastfeeding for at least 2 months decreased the risk of postpartum relapse.