In ten clinical studies of cladribine, used to treat multiple sclerosis (MS), study subjects were asked to use contraception to avoid getting pregnant. However, some women did become pregnant, as did the female partners of some men with MS who took part in the studies. We report the outcomes for these pregnancies as part of a large safety analysis.

There were 70 pregnancies in total; 49 in the cladribine group and 21 in the placebo group. The outcomes for these pregnancies (including abortions and live births) were very similar for the two groups.

These findings are what we would expect for women in the general population, as well as women with MS who become pregnant. A new study is being conducted to obtain more information on pregnancies when women are treated with cladribine for MS.