Myasthenia gravis and pregnancy: a reappraisal of thymectomy.

A retrospective review of pregnancy in patients with myasthenia gravis at Duke University was conducted. Twelve new cases of pregnancy in eight myasthenic mothers are reported. In general, thymectomy was the primary treatment modality in these patients and preceded the gestational period in all cases. The clinical course of myasthenia gravis in these pregnancies prompted a literature review of previous case reports. Comparison of clinical symptomatology, course of disease, and maternal and perinatal morbidity and mortality revealed that the incidence of clinical exacerbation was less in the thymectomy than in the nonthymectomy group. The role of the thymus in the pathogenesis of myasthenia gravis is reviewed. The rationale for the use and timing of thymectomy in the treatment of the myasthenic patient is presented. This review supports the continued use of thymectomy for the initial treatment of the young, nonpregnant myasthenic female patient.