Paternal therapy with disease modifying drugs in multiple sclerosis and pregnancy outcomes: a prospective observational multicentric study

Background: Most of Multiple Sclerosis (MS) patients undergo disease modifying drug (DMD) therapy at childbearing age. The objective of this prospective, collaborative study, was to assess outcomes of pregnancies fathered by MS patients undergoing DMD. Methods: Structured interviews on pregnancies fathered by MS patients gathered in the Italian Pregnancy Dataset were collected; pregnancies were divided according to father exposure or unexposure to DMD at time of procreation. Treatment were compared with multivariable logistic and linear models. Results: Seventy-eight pregnancies fathered by MS patients were tracked. Forty-five patients were taking DMD at time of conception (39 beta-interferons, 6 glatiramer acetate), while 33 pregnancies were unexposed to DMD. Seventy-five pregnancies ended in live-births, 44 in the exposed and 31 in the unexposed group. No significant differences between the two groups were found in the risk of spontaneous abortion or malformations (p > 0.454), mean gestational age (p = 0.513), frequency of cesarean delivery (p = 0.644), birth weight (p = 0.821) and birth length (p = 0.649). In comparison with data of the Italian general population, the proportion of spontaneous abortion and caesarean delivery in exposed pregnancies fell within the estimates, while the proportion of pre-term delivery in the exposed group was higher than expected. Conclusions: Our data indicate no association between paternal DMD exposure at time of conception and risk of spontaneous abortion, adverse fetal outcomes and congenital malformations. Further studies clarifying the role of DMD fathers intake prior and during pregnancy are desirable, to supply guidelines for clinical practice.