Multi-minicore disease with susceptibility to malignant hyperthermia in pregnancy.

Multi-minicore disease (MmD) is a congenital non-progressive or slowly progressive myopathy associated with multifocal degeneration of muscle fibers. Obstetric management for patients with MmD has not been described previously. A 25-year-old primigravida with a history of muscular weakness from birth was diagnosed with MmD and found to be susceptible to malignant hyperthermia (MH) by muscle biopsy at 28 weeks of gestation. Pregnancy proceeded uneventfully and she had a successful vaginal delivery under sufficient preparation for the possible occurrence of MH. Pregnant women who exhibit myopathic symptoms from childhood should consult an anesthesiologist prior to delivery.