Relapse risk before, during and after pregnancy in MOG antibody-associated disorder: a two-center retrospective study

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described inflammatory disorder of the central nervous system. Unlike other demyelinating disorders of the central nervous system, the impact of pregnancy and the postpartum period on MOGAD disease activity remains uncertain. A better understanding of pregnancy-related relapse risk in MOGAD is essential to inform management.

We conducted a retrospective chart review of all patients followed in two large referral centers in the Northeastern United States with a confirmed diagnosis of MOGAD and at least one post-MOGAD onset pregnancy carried to the third trimester. Demographic, neurological, obstetric, and treatment-related data were extracted from electronic medical records, centered around the 12-month pre-pregnancy, pregnancy, and 12-month post-pregnancy periods, for each of which the annualized relapse rates (ARRs) were calculated.

We identified 15 women diagnosed with MOGAD who had 22 post-MOGAD onset pregnancies. No relapses were observed during any of the 22 pregnancies, but 2 relapses were observed in the postpartum period in a single patient with a steroid-dependent relapsing course. The mean ARR was 0.26 ± 0.86 during the 12-month pre-pregnancy period, 0 during pregnancy, and 0.09 ± 0.42 in the 12-month postpartum period. Twelve of 22 pregnancies (55 %) were exposed to disease-modifying therapy (DMT) at conception, and 59 % were continued on DMT into the postpartum period. Obstetric complications were recorded in 5 of 22 pregnancies (22 %).

The two main findings of our retrospective study are: 1) the relapse risk is very low during pregnancy in women with MOGAD, and 2) postpartum relapse risk does not appear to be elevated in patients with a low pre-pregnancy relapse rate. Approximately half of the women in our series were receiving disease-modifying therapies during the postpartum period, which may have decreased relapse rates. Larger prospective studies are needed to validate our observations.