Résumé
Background and objectives: Older studies reported an increased risk of relapse after in vitro fertilization (IVF) in women with multiple sclerosis (MS), which has not been confirmed by more recent works. All these studies had several limitations, such as small sample sizes, absence of a control population, or lack of neurologic validation of the relapses. The aim of this study was to determine the risk of relapse after IVF in women with MS.Methods: This retrospective cohort study included all women with MS who underwent IVF between 2009 and 2019 and a control group of women with MS who did not undergo IVF matched on age, MS duration, number of relapses, and MS-specific treatments in the previous year. Data on MS (disease duration, treatments, and relapses) were from the French MS Registry (OFSEP), whereas data on IVF (number of procedures, stimulation protocol type, and outcomes) were from the French national health insurance database. For this, the 2 databases were linked by indirect matching.Results: In total, 115 women with MS underwent 199 IVF procedures (mean age at first IVF: 33.9 ± 4.0 years; 45.2% had ≥2 IVF procedures), and 175 IVFs (88.0%) could be matched to specific patients. The risk of relapse in the 3 months after index date was the same in both IVF group and control group (0.06 relapse per patient-year), as confirmed also by the before-after analysis in the IVF group (0.06 vs 0.08).Discussion: This study, using a 10-year clinical and administrative dataset, did not find any increased risk of relapse after IVF. The maintenance of disease-modifying therapies until IVF was a determining factor in reducing the risk of relapse.