Birth Outcomes in Newborns Fathered by Men with Multiple Sclerosis Exposed to Disease-Modifying Drugs

The aim of this study was to determine the incidence of births fathered by men with multiple sclerosis (MS) exposed to a disease-modifying drug (DMD) around the time of conception, and investigate the association between DMD exposure and birth outcomes in newborns of exposed and unexposed MS fathers. Population-based databases in British Columbia (BC), Canada, (the BCMS database, Vital Statistics Birth Registry, Population Data BC Consolidation File/Census GeoData, BC PharmaNet and the BC Perinatal Database Registry) were linked in this retrospective cohort study (1996 to 2010). Multivariate models were used to examine the association between interferon-beta (IFN beta) or glatiramer acetate (GA) exposure (within 64 days prior to or at conception; i.e., the duration of spermatogenesis) with birth weight and gestational age of newborns. Of 195 births fathered by men with relapsing-onset MS, 80 births (41 %) were to fathers treated with a DMD before their child was born, with 53/195 (27 %) exposed within 64 days prior to or at the time of conception. Of the 53 exposed births, 37 were to IFN beta and 16 to GA. Mean birth weight of IFN beta-exposed and GA-exposed newborns was similar to that of unexposed newborns (adjusted difference: -107 g for both, p > 0.3). IFN beta-exposed and GA-exposed newborns also had comparable mean gestational ages relative to unexposed newborns (adjusted difference: -0.5 and -0.3 weeks, respectively, p > 0.2). About one in three would-be fathers with MS were exposed to IFN beta or GA around the time of conception; there was no compelling evidence to suggest that exposure was associated with either lower birth weight or gestational age.