Plauché W C
Louisiana State University, School of Medicine, New Orleans.
Clin Obstet Gynecol. 1991 Mar;34(1):82-99.
Myasthenia gravis is a complex autoimmune disorder. Anti-AChR antibodies destroy elements of the postsynaptic membrane of the myoneural junction in affected muscle groups. This results in decreased nerve-impulse transmission. Myasthenic patients have diminished skeletal muscle strength and tire rapidly with exercise. Pregnancy threatens maternal myasthenic exacerbation and crisis, particularly early in the puerperium. The medication requires frequent adjustment during pregnancy due to changing requirements and physiologic changes in absorption and excretion. Myasthenia results in an increase in maternal mortality, morbidity, pregnancy wastage, and premature labor. Anticholinesterase medications and corticosteroids are the mainstays of medical therapy of maternal MG. Thymectomy, plasmapheresis, immunosuppressant drugs, gamma globulin, and ACTH are adjuvants of varying usefulness. Enforced rest periods, a tranquil environment, and prompt treatment of intercurrent infections are important for myasthenic mothers. The management of myasthenic crisis requires hospital intensive care with mechanical respiratory support and careful monitoring of blood gases. Plasmapheresis is an effective means of controlling crises. It is usually combined with intensive steroid and or immunosuppressant therapy. The myasthenic mother undertakes pregnancy with increased risk to herself and her infant. There is a 40% chance of exacerbation of her MG during pregnancy and an additional 30% risk in the puerperium. Maternal mortality risk is approximately 40 per 1,000 live births. Perinatal mortality approximates 68 per 1,000 births, five times that of uncomplicated pregnancies. Modern management minimizes these risks to the extent that pregnancy is not precluded in myasthenic women. A good outcome depends on meticulous maternal and fetal prenatal surveillance and early detection and management of exacerbations. Facilities and trained personnel must be available to support labor and manage vaginal or operative delivery. Intensive care of myasthenic crises is critical to the prevention of maternal complications and death.
重症肌无力是一种复杂的自身免疫性疾病。抗乙酰胆碱受体（AChR）抗体破坏受累肌肉群中肌神经接头突触后膜的成分。这导致神经冲动传递减少。重症肌无力患者骨骼肌力量减弱，运动后很快疲劳。妊娠会威胁到母亲重症肌无力的加重和危象，尤其是在产褥期早期。由于吸收和排泄需求的变化以及生理变化，孕期药物需要频繁调整。重症肌无力会导致孕产妇死亡率、发病率、妊娠丢失和早产增加。抗胆碱酯酶药物和皮质类固醇是母亲重症肌无力药物治疗的主要手段。胸腺切除术、血浆置换、免疫抑制药物、γ球蛋白和促肾上腺皮质激素是不同程度有用的辅助治疗方法。强制休息、安静的环境以及及时治疗并发感染对重症肌无力母亲很重要。重症肌无力危象的处理需要在医院重症监护下进行机械通气支持并仔细监测血气。血浆置换是控制危象的有效方法。它通常与强化类固醇和/或免疫抑制治疗联合使用。重症肌无力母亲怀孕对自身和婴儿都有更高风险。孕期她的重症肌无力加重的几率为40%，产褥期还有30%的额外风险。孕产妇死亡风险约为每1000例活产40例。围产期死亡率约为每1000例出生68例，是无并发症妊娠的5倍。现代管理将这些风险降至最低，以至于重症肌无力女性并非绝对不能怀孕。良好的结局取决于对母亲和胎儿细致的产前监测以及对病情加重的早期发现和处理。必须具备设施和训练有素的人员来支持分娩并处理阴道分娩或手术分娩。对重症肌无力危象的重症监护对于预防母亲并发症和死亡至关重要。
