Pre-Diagnosis Oral Contraceptive Use may delay PIRA Risk in Multiple Sclerosis: Study

A new study published in the Journal of Neurology, Neurosurgery, and Psychiatry found that women who used oral contraceptives before being diagnosed with multiple sclerosis (MS) experienced a lower risk of progression independent of relapse activity (PIRA). Notably, contraceptive use delayed the onset of a PIRA event by approximately 2.5 years. However, the study found no significant association between the duration of contraceptive use and PIRA risk.

Decades of epidemiological research have demonstrated that women are more likely than men to suffer multiple sclerosis, but it is still unknown how sex hormones affect the course of the illness. A well-known clinical feature in multiple sclerosis is the disease-modifying impact of pregnancy, which increases the chance of relapse during the postpartum phase but decreases it during the third trimester.

When taken as a whole, these two clinical findings suggest that research on sex-related characteristics might provide important new information on the pathogenic elements of MS. Thus, to determine if sex hormone-related variables affect of progression independent of relapse in women with MS over an extended period of time, regardless of relapse activity, Antonino Giordano and team carried out this experiment.

Using information from an environmental survey conducted between 2019 and 2023, the study examined a total of 1210 female MS patients from the San Raffaele MS Center. The 12-week documented disability progression, irrespective of recent relapses (less than 30 days), was referred to as PIRA. The impact of hormone-related parameters on PIRA risk was evaluated using Cox proportional-hazard models, which were adjusted for confounding variables.

Prior to receiving an MS diagnosis, patients who used oral contraceptives had a delayed median time to the first PIRA incident (9.94 vs. 7.5 years; HR=0.74; 95% CI 0.61 to 0.89; p=0.0018) and a 26% reduced risk of PIRA. On the other hand, a shorter duration to PIRA was linked to menopause at diagnosis (HR=1.82; 95% CI 1.24 to 2.67; p=0.0022) and pregnancy before to diagnosis (HR=1.22; 95% CI 1.006 to 1.47; p=0.043).

There were no discernible changes between fertility treatment, irregular menstruation, or abortion. Overall, this study supports the significance of sex hormones in MS and encourages more prospective research on oral contraceptives to reduce disease progression by indicating that early use of these methods may postpone the development of future disabilities.

Source:

Giordano, A., Giliberti, A., Clarelli, F., Misra, K., Mascia, E., Sorosina, M., Visentin, G., Margoni, M., Moiola, L., Rocca, M. A., Filippi, M., Esposito, F., & Clinical SanRaf MS Study Group. (2025). Sex hormone-related factors and the risk of PIRA in women with multiple sclerosis. Journal of Neurology, Neurosurgery, and Psychiatry. https://doi.org/10.1136/jnnp-2024-335547