How does myasthenia gravis affect pregnancy?
Pregnant women with MG often have more weakness and fatigue because of the added weight and effort of pregnancy. Some pregnancy complications may be more likely in women with MG. Preterm labor (labor before 37 weeks of pregnancy) is more likely. It is thought that anticholinesterase medications used to treat MG may cause uterine contractions. Myasthenic crisis may be more likely during the stress of labor. Delivery of the baby may be more difficult in women with MG. While labor itself is not affected by MG (the uterus is a smooth muscle), the muscles needed for pushing can be affected. This may make forceps and vacuum-assisted deliveries more likely. A medication called magnesium sulfate that is commonly used for treating high blood pressure and preterm labor should not be used in women with MG. This drug blocks the nerve-muscle connections and can worsen MG muscle weakness. Between 10 and 25 percent of babies born to women with MG may have neonatal myasthenia gravis. This occurs when
