To asses pregnancy outcomes and disease activity after cladribine treatment in women with multiple sclerosis (MS).

Information on pregnancy outcomes after cladribine exposure in women with MS is scarce and data on disease activity during pregnancy and postpartum is also lacking.

Pregnancies after cladribine treatment documented in the German Multiple Sclerosis and Pregnancy Registry (DMSKW) are presented. Information on pregnancy outcomes and disease course was collected with a standardized questionnaire in regular telephone interviews during pregnancy and postpartum. For descriptive analysis, this cohort was stratified to last cladribine intake i) after last menstrual period (LMP), ii) between LMP and 6 months prior to LMP and iii) more than 6 months prior to LMP.

28 pregnancies in women with MS occurred after cladribine treatment, two with pregnancy exposure after LMP (median exposure duration 24 days; range 19 – 29), 14 with pregnancy exposure during the last 6 months prior to LMP (median exposure duration 114,5 days; range 1 – 180) and 12 without pregnancy exposure (median exposure duration 218 days; range 189 – 576). So far, 12 healthy babies and one elective abortion due to social indication were reported. 14 pregnancies are ongoing (normal pregnancy course up to now) and one woman is lost to follow up. No congenital abnormality was reported. Only one relapse occurred among 12 women with completed pregnancy follow-up (8.4%) and one postpartum relapse among 8 women with at least 3 months postpartum follow up (12.5%). Updated information will be presented at the time of the meeting.

Our data adds useful information on pregnancies with healthy newborns after cladribine treatment, but is limited by the very small sample size. It is important to counsel women to avoid pregnancies within 6 months after the last intake of cladribine and to use effective contraception.