To assess pregnancy outcomes in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO) treated with Rituximab (RTX).

Pregnancy is a major concern for MS and NMO patients, given that many of those affected by these disorders are females of childbearing age. Anti-CD20 monoclonal antibody medications are increasingly used in management of these patients. However, the drug effect on disease activity pre-, during, and post-gestation, as well as pregnancy outcomes, are lacking.

Retrospective chart review was performed on female patients of childbearing age treated with RTX at NYU MS Comprehensive Care Center. Pregnancy outcomes and disease activity pre-, during, and post-delivery were collected and analyzed for patients with Rituximab treatment within twelve months of pregnancy.

24 pregnancies were identified in 22 patients (17 MS and 5 NMO). The average age was 35.4yrs (range: 23-49yrs). The average disease duration at time of pregnancy (ToP) was 5.65yrs (range: 0-18yrs), with an average duration of RTX treatment at ToP 13.8mo (range: 1-66 mo). 54% of patients experienced a relapse 12mo prior to pregnancy. Two patients showed Gd+ lesions on MRI, and eight showed new T2 lesions on MRI. 18% of patients experienced a relapse during pregnancy, and 32% of patients experienced a relapse within 12mo postpartum. During that time, three showed new T2 lesions on MRI. 

RTX exposed patients had a 25% miscarriage rate.

Experience with anti-CD20 monoclonal antibodies in exposed pregnancies is limited, although preliminary data with RTX is encouraging. Further studies are need to produce comprehensive guidelines to help with family planning counseling.