Article

The influence of pregnancy in multiple sclerosis (MS) has been a matter of controversy for a long time. Women with MS were often discouraged to envisage pregnancy. The Pregnancy in Multiple Sclerosis (PRIMS) study was the first large-scale prospective study aimed at assessing the possible influence of pregnancy and delivery on the clinical course of MS. Two hundred and fifty-four women with a diagnosis of MS were included during pregnancy and followed-up till the end of the second year post partum. The results were a reduction in the relapse rate during pregnancy, in comparison to the year before pregnancy, especially marked in the third trimester, and a significant increase in the relapse rate in the first trimester post partum. From the second trimester post partum on however, the relapse rate did not significantly differ from the pre-pregnancy rate. About one third of the women experienced a post partum relapse. Pregnancy did not influence disability progression. The clinical factors likely to predict a relapse in the three months after delivery were analyzed by logistic regression analysis. Women with a greater disease activity in the year before pregnancy and during pregnancy had a higher risk of relapse in the post partum three months. Neither breast-feeding, nor epidural analgesia correlated with presence of a post partum relapse. When comparing the predicted and observed status however, only 72 percent of the women were correctly classified by the multivariate model. It seems unwise therefore to use this kind of model to select women that would benefit from a putative preventive therapy. The PRIMS study had other major consequences: it fostered the development of specific therapeutic strategies to prevent post partum relapses (IV immunoglobulins, IV methylprednisolone), and suggested a potential role of sexual hormones in the natural history of MS during pregnancy and the post partum, therefore identifying them as a preferential target for prevention. The preventive effect of progesterone combined with estradiol on post partum relapses will be tested in a large-scale randomized and placebo-controlled European trial, the POPART'MUS study.

Langue : FRANCAIS