© 2017 The Japanese Society of Internal Medicine. We herein report the case of a 46-year-old pregnant woman with anti-muscle specific kinase (MuSK) antibody-positive myasthenia gravis (MG) who showed pregnancy-induced hypertension and developed respiratory failure at 30 weeks and 5 days of pregnancy, and who underwent an emergency caesarean section (CS). Her MG symptoms gradually improved in the subsequent weeks. The premature baby with positive MuSK antibodies was successfully delivered, but the male baby required temporary artificial ventilation. However, his condition also gradually improved over time. The present case suggests that an emergency CS could rescue both the mother, who was in critical condition, and the prematurely born baby, even when suffering from acute respiratory insufficiency.