Abortion induces reactivation of inflammation in relapsing-remitting multiple sclerosis

Objective To investigate clinical and radiological outcomes of women with relapsing-remitting multiple sclerosis (RRMS) undergoing abortion.Methods An independent, multicentre retrospective study was conducted collecting data from eight Italian MS centres. We compared the preconception and postabortion annualised relapse rate (ARR) and number of Gadolinium enhancing (Gd+) lesions, by analyses of covariance. Variables associated with postabortion clinical and MRI activity were investigated using Poisson regression models; each abortion was considered as a statistical unit.Results From 1995 to 2017, we observed 188 abortions (17 elective) in 153 women with RRMS. Abortions occurred after a mean time of 9.5 (4.4) weeks from estimated conception date. In 86 events out of 188, conception happened during treatment with disease modifying drugs. The mean postabortion ARR (0.63 +/- 0.74) was significantly increased (p=0.037) compared with the preconception year (0.50 +/- 0.71) as well as the postabortion mean number of new Gd+ lesions (0.77 +/- 1.40 vs 0.39 +/- 1.04; p=0.004). Higher likelihood of relapses was predicted by higher preconception ARR, discontinuation of preconception treatment and elective abortion; the occurrence of new Gd+ lesions was associated with higher preconception number of active lesions, discontinuation of preconception treatment, shorter length of pregnancy maintenance and elective abortion.Conclusions A bortion was associated with clinical and radiological inflammatory rebound remarkably in the first 12 months postevent. Deregulated proinflammatory processes arising at the early stages of pregnancy might play a role both in MS reactivation and abortion. Women with MS should be counselled about these risks of abortion and followed up accordingly.