Pregnancy outcome in women with myasthenia gravis

Abstract

Backgrounds: Myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction characterized by variable weakness and easy fatigability of skeletal muscles. The disease is twice as common in females and often occurs, during childbearing age. We investigated the clinical course of MG in pregnant women, the relationship between MG and pregnancy and puerperium complications.Methods: This study was a single center retrospective and case-control study. We included 38 pregnant women with MG treated at our hospital from January 1, 2005 to June 30, 2013. The normal control group, included women who gave birth at our hospital and had no medical, surgical, or psychological treatment; we selected age-matched controls from these women using random numbers. We observed the clinical course of MG during pregnancy, delivery, and puerperium; investigated several factors potentially affecting the clinical course of MG; and compared adverse pregnancy outcomes between MG mothers and normal controls.Results: Of 49 pregnancies, 8 ended in abortions and 41 in live births, the latter including 21 vaginal deliveries and 20 cesarean sections. Of the 41 pregnancies ending in live birth, MG exacerbation occurred in 10 pregnancies, with symptoms at onset appearing to affect the likelihood of such exacerbation; there were more patients who presented with primarily ocular symptoms at onset among those who did not experience exacerbation during pregnancy (25, 80.6%) than among those who did (4, 40.0%) [P =0.036]. There was no statistically significant difference in the incidence of adverse pregnancy outcomes between MG mothers and normal controls (MG vs. control: preterm birth 4.9% vs. 17.1% [P =0.068], low birth weight 14.6% vs. 12.2% [p=0.763], small for gestational age 9.8% vs. 2.4% [P =0.208]) except for cesarean section (48.8% vs. 26.8% [P =0.031]). Aside from these four,

several other major and minor maternal and neonatal complications occurred, including 1 case of transient neonatal myasthenia gravis.Conclusion: MG patients presenting with primarily ocular symptoms at onset may be less likely to experience exacerbation during pregnancy, and MG mothers have no more risk of adverse pregnancy outcomes than normal mothers. We suggest that MG patients with limb or bulbar symptoms at onset should receive more attention during pregnancy; however, routine obstetric management is generally sufficient for pregnant MG patients with appropriate MG treatment.