Offspring Number Does Not Influence Reaching the Disability's Milestones in Multiple Sclerosis: A Seven-Year Follow-Up Study.

OBJECTIVES Data on pregnancy long-term effects on multiple sclerosis (MS) course are still controversial; whether experiencing more than one pregnancy exposes one to risk of the disability's accrual is still unknown. We investigated differences existing in terms of disability progression among women with MS (wwMS) who had one or more children after their MS onset. METHODS Monoparous and multiparous wwMS were enrolled from the Catania MS Center, Italy, in a monocenter retrospective study. A Cox proportional hazards model was used to examine the effect of the number of parities on time from MS disease onset to EDSS 4.0 and 6.0. The study protocol was approved by the local Ethical Committee. RESULTS During the seven years of observation, 32.1% and 23.2% of the monoparous group reached expanded disability disease status (EDSS) 4.0 and 6.0 respectively, compared to 13.3% and 3.3% of the multiparous group (p = 0.057 and p = 0.017; respectively). The Kaplan-Meier curve analysis showed no statistically-significant differences between the two groups in reaching the two milestones. The multiparous group showed a longer time to reach the EDSS 4.0 (3.5 vs. 2.6 years, log-rank 0.57, p = 0.45). The Cox regression analysis showed that the EDSS at the time of first pregnancy (Exp(B) 9.4, CI 4.5-19.7, p< 0.001) and the time from MS onset to first pregnancy (Exp(B) 0.96, CI = 0.93-0.98, p < 0.05) were significant predictors of reaching the EDSS 4.0, whereas a model including only the EDSS one year after the first pregnancy significantly predicted (Exp(B) value of 6.4, CI 2.6-15.4, p < 0.001) the reaching of EDSS 6.0. CONCLUSIONS Our results suggest that experiencing more than one pregnancy could not convey a different clinical outcome in wwMS. Further research is needed to confirm our results.