Is in utero early-exposure to interferon beta a risk factor for pregnancy outcomes in multiple sclerosis?

There exist controversial and discrepant results on the risk of spontaneous abortions and teratogenesis induced by interferon treatment in people with MS.Aim of this study is to evaluate risks of the administration of INFbeta related not only to the foetus, but also to children development up to 12-months developmental milestones.

The study design is retrospective with a follow-up of babies until 18-months of their life. Thirty-eight women out of 240 with MS followed-up at Clinic MS Center of the University Hospital of Catania, Italy became pregnant in the period june 1997-may 2006. Patients were grouped into three arms: in utero exposed to INFbeta, never treated and patients who discontinued INFbeta before starting conception. Pregnancy outcomes, birth weight, 12-month developmental milestones were collected with an ad hoc questionnaire.

Newborns of in utero exposed to INFbeta patients were little smaller for birth weight (3079.6 +/- 313.3 g), but not statistically significant, if compared with the other groups. Developmental milestones appeared within the normal range in all groups.

Our results were particularly favourable on pregnancy outcomes, because we observed only a smaller birth weight which was not detrimental for the further development of children. We believe that INFbeta therapy might not be considered to be a reason for interruption of an intact pregnancy once the drug has been discontinued until delivery.