Effectiveness and safety of immunosuppressive therapy in neuromyelitis optica spectrum disorder during pregnancy

Abstract

Objective: To evaluate the effectiveness and safety of immunosuppressive therapy in neuromyelitis optica spectrum disorder (NMOSD) during pregnancy.

Methods: Sixteen NMOSD patients who had at least one pregnancy after NMOSD onset were enrolled. The patients were divided into two groups according to whether they received immunosuppressive therapy during pregnancy. The annual relapse rate (ARR) before pregnancy (BP); during the first (DP1), second (DP2), and third trimesters (DP3); first trimester postpartum (PP1); and second trimester postpartum (PP2) were calculated. The Expanded Disability Status Scale (EDSS) was used to evaluate the degree of disability. Pregnancy outcomes were recorded and the children were followed up and their health condition was evaluated.

Results: In the group taking prednisone alone or in combination with azathioprine as immunosuppressive therapies, there was no difference among ARRs of each period (DP1, DP2, DP3, PP1, PP2) and BP. Compared with EDSS BP, EDSS increased slightly 6months postpartum with no statistical significance (p=0.102). In the group without immunosuppressive therapy, ARR increased during PP1 (p=0.014) and EDSS increased 6months postpartum as compared to BP (p=0.017). Moreover, the added EDSS value was higher in the group without immunosuppressive therapy than in the group with therapy (p=0.038). In 22 pregnancies from 16 patients, 16 pregnancies ended in live births and 6 pregnancies ended in abortions, including 2 spontaneous and 4 induced abortions. None of the children had congenital diseases or malformations. There were no records of abnormal growth among the children during 6months to 12years of follow-up.

Conclusion: Untreated women showed a propensity for disease relapse in PP1 and increased degree of disability postpartum. Immunosuppressive therapy during pregnancy and postpartum period can reduce the risk of relapse and degree of disability. Immunosuppressive therapy with low-dose prednisone was relatively safe. However, the safety of azathioprine during pregnancy remains unclear and needs future reevaluation.

Keywords: Annual relapse rate; Expanded Disability Status Scale; Immunosuppressive therapy; Neuromyelitis optica spectrum disorder; Pregnancy.