The effects of long-term exposure to disease-modifying drugs during pregnancy in multiple sclerosis

Abstract Background and objective Women with multiple sclerosis (MS) who intend to get pregnant are often advised to discontinue disease modifying therapy (DMT) prior to conception. This recommendation is not based on medical evidence and may interfere with disease control by immunomodulatory drugs. The present study was designed to help discuss the effect of DMT for MS on pregnancy and on disease course. Patients and methods Retrospective data from 152 pregnancies of 132 women with MS were collected by the physician in charge of the case. All data were entered into a specific file for qualitative and quantitative statistical analysis. Results From the total group of patients, 89 pregnancies occurred without any exposure to MS drugs, while 61 pregnancies occurred with at least eight weeks of exposure to MS immunomodulatory drugs. The rate of obstetric and neonatal complications was similar in both groups, except for the newborn weight and height which was smaller for mothers receiving medications. Mothers’ post-delivery relapse rate and EDSS scores in the follow-up period were significantly higher in the absence of treatment. Conclusion It is possible that, with further such supportive data, international guidelines on MS treatment in young women who intend to get pregnant may need to be revised.