Unusual Labor-Onset Flare of Generalized Myasthenia Gravis in Pregnancy: A Case Report

Background: Myasthenia Gravis (MG) is the most prevalent disorder affecting neuromuscular transmission, characterized by fluctuating weakness of voluntary muscles attributed to the presence of autoantibodies that target components of the neuromuscular junction, predominantly the acetylcholine receptor (AChR). This condition exhibits a notable flare for MG in a woman during her first labour. The management of MG during pregnancy is challenging due to various physiological changes, concerns regarding the safety of pharmacological interventions, and the inherent risks associated with myasthenic exacerbation or crisis. Case Presentation: We report the case of a 27-year-old primigravida at 40+ weeks of gestation with an established diagnosis of generalized seropositive MG and a history of prior thymectomy secondary to thymic carcinoma. Labor induction was enacted; however, she subsequently experienced an exacerbation of her MG, manifesting as ptosis and increased muscle weakness. In response, her oral dosage of pyridostigmine was elevated, and a high-potassium diet was implemented. Due to a failure to progress in labor, a grade 2 emergency cesarean section was conducted. Postoperatively, she exhibited significant improvement and was subsequently discharged with comprehensive postpartum care and counseling from the multidisciplinary team. Conclusion: This case underscores the critical need for early recognition and proactive MDT planning, as well as the implementation of tailored pharmacological and obstetric strategies for managing MG during pregnancy. The management of MG during pregnancy should prioritize the maintenance of disease control while simultaneously minimizing potential risks associated with medication use and delivery-related stressors.