Myasthenia Gravis in Pregnancy: Case Series and Systematic Review

Abstract

Background: Myasthenia gravis (MG) is an autoimmune disease which can affect reproductive-aged women and impact pregnancy outcomes. Objectives: To systematically review pregnancy outcomes for patients with MG. Search Strategy: Ovid MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, PubMed (Non-Medline records), Web of Science, and LILACS databases were systematically searched for pregnancies complicated by MG. Selection Criteria: Human studies of five or more subjects reporting outcomes of MG in pregnancy published in any language. Data Collection and Analysis: Following identification and review of relevant studies, data on study characteristics, MG subtypes, treatment, disease and pregnancy outcomes were extracted. Assessment of bias was performed using the National Institutes of Health Quality Assessment Tool for Case Series. In addition, cases of MG in pregnancy managed at our centre were identified and outcomes included in the analysis. Main Results: In total, 32 publications met inclusion criteria for systematic review, for a total of 33 unique data sets including 48 cases at our institution. In total, outcome data was available for 824 pregnancies complicated by MG. Overall risk of MG exacerbation was 33.8% with a 6.4% risk of myasthenic crisis in pregnancy and 8.2% postpartum. Spontaneous vaginal delivery occurred in 56.3% of pregnancies. The risk of transient neonatal myasthenia gravis (TNMG) was 13.0%. Conclusions: One third of pregnant MG patients will experience an exacerbation with 6.4% and 8.2% experiencing myasthenic crisis in pregnancy and postpartum respectively. More than half of MG patients had a spontaneous vaginal birth. The risk of TNMG is 13%