Paper
Monday, November 5, 2007
364
Care of the Woman with Myasthenia Gravis Throughout Pregnancy and Birth
Patricia A. Heale, MSN, RNC, Maternal-Child Health, Newton-Wellsley Hospital, Newton, MA, USA
| Learning Objective #1: describe the effects of pregnancy and birth on the parturient with Myasthenia gravis. |
| Learning Objective #2: identify the use of drug and alternative treatments for the parturient with Myasthenia gravis. |
Myasthenia gravis (MG) is an auto-immune disorder of the neuromuscular junction characterized by varying degrees of weakness within the body’s skeletal muscles especially the ocular, bulbar, and limb muscles. MG affects twice as many women as men and is likely to strike women during childbearing years. Worsening of MG symptoms occurs in 30% to 41% of parturients with the most severe symptoms seen when pregnancy occurs within one year of diagnosis. Remission during pregnancy has been seen in 29% of women and no change in condition during pregnancy has been noted in 32% of women. Treatment of MG is complicated by the routine physiologic changes of pregnancy including nausea and vomiting, increased blood volume, changes in renal clearance, and alterations in gastrointestinal motility. Anticholinesterase medications are the first line of treatment for patients with MG but during pregnancy medications may need to be increased due to volume expansion and delayed gastric emptying; other medications include: cyclosporine A, corticosteroids, and azathioprine. The nurse caring for the parturient with MG should take a thorough history including medications, prenatal testing, and laboratory data. A thorough assessment to gauge the patient’s stage of MG, potential for infection, and her risk for myasthenic crisis is also needed. The non-stress test can be unreliable as can be kick count records and in labor continuous fetal monitoring is indicated. Ongoing evaluation of the parturient’s respiratory status and risk of infection is essential as the stress of labor increases the risk of myasthenic crisis. Cesarean birth poses multiple risks and should only be used for obstetrical indications or myasthenic crisis. A small percentage of newborns may show signs of Neonatal Myasthenia gravis (NMG) between 12 hours to up to three months after delivery. In rare cases respiratory failure may require intubation and mechanical ventilation of the newborn.