Neuromuscular disorders in pregnancy.

Many neuromuscular disorders preexist or occur during pregnancy. In some cases, pregnancy unmasks a latent hereditary disorder. Most available information is based on case reports or series or retrospective clinical experience or patient surveys. Of special interest are pregnancy-induced changes in disease course or severity and likelihood for baseline recovery of function postpartum. Labor and delivery present special challenges in many conditions that affect skeletal but not smooth (uterine) muscle; so labor complications must be anticipated. Anesthesia for cesarean section surgery requires special precautions in many disorders. The types of conditions reviewed are broad and include examples of autoimmune, hereditary, and compressive/mechanical processes. Disorders include carpal tunnel syndrome and other focal neuropathies, Bell palsy, myasthenia gravis, and other neuromuscular junction disorders, acute and chronic inflammatory neuropathy, hereditary and acquired muscle diseases, spinal muscular atrophy, amyotrophic lateral sclerosis, channelopathies, autonomic neuropathy, and dysautonomia. Many commonly used therapies have fetal animal but no proven human toxicity concerns, complicating treatment and risk decisions. Weaning off effective therapeutic agents or preemptive aggressive treatment or surgery prior to planned pregnancy is an option in some conditions.