Disease modifying therapies and disease activity during pregnancy and postpartum in a contemporary cohort of relapsing Multiple Sclerosis patients.

BACKGROUND: In Multiple Sclerosis (MS) women, therapeutic management for pregnancy planning and during pregnancy still represents a challenge regarding timing of disease-modifying therapies (DMT) stop, risk of disease reactivation and potential fetal toxicity. The objective of this study was to describe disease activity during pregnancy and postpartum depending on treatment status before conception in women with MS. METHODS: 339 MS patients who have achieved a pregnancy between 2007 and 2017 were included. Women were classified according to their exposure to DMT in the 18 months period prior to pregnancy (untreated / first- / second/third-line treatment). RESULTS: 122 women were not exposed to DMT prior to conception, whereas 147 were exposed to first-line DMT and 70 to second/third line DMT (73% to natalizumab and 23% to fingolimod) before conception. In the first-line group, the ARR decreased from 0.39 during the year before conception to 0.21 during pregnancy, whereas it increased in the second/third-line group from 0.59 to 0.78. 47.1% of the second/third-line group faced at least one relapse during pregnancy and the time from conception to first relapse was significantly shorter in this group (p < 10-4). The risk of relapse during pregnancy and postpartum was associated with occurrence of pre-conception relapses and second/third line DMT exposure before pregnancy. CONCLUSION: Careful consideration should be given to natalizumab and fingolimod exposed patients before conception as they are at higher risk of reactivation of MS during pregnancy.

COPP-MS: COrticosteroids during the Post-Partum in relapsing Multiple Sclerosis patients.

BACKGROUND: No specific treatment has demonstrated its effectiveness to prevent post-partum relapses for multiple sclerosis (MS) women. OBJECTIVE: To assess the effectiveness of preventive high-dose corticosteroids in the post-partum period by comparing two strategies: (1) no preventive treatment and (2) standardized preventive treatment. METHODS: We selected five French Multiple Sclerosis centers using the same post-partum strategy for their patients-either high-dose steroids (treating centers TC) or no treatment (non-treating centers NTC). We included relapsing-remitting multiple sclerosis women who delivered between January 2007 and January 2017. Our primary outcomes were the time from delivery to first relapse, EDSS progression and MRI activity between patients of treating centers and non-treating centers, after propensity-score weighting. RESULTS: 350 patients were included (116 from treating centers, 234 from non-treating centers). For both groups, the annualized relapse rate decreased during pregnancy (0.28 in treating centers and 0.34 in non-treating centers during the third trimester) and increased during the first post-partum trimester (0.45 and 0.69, respectively) with 11% and 14% (NS) of patients facing at least one relapse, respectively. Our primary outcomes were not statistically different between both groups. CONCLUSION: This study provides class III evidence that systematic high-dose corticosteroids are not associated with a reduced inflammatory activity during the post-partum period in multiple sclerosis patients.