Multiple smooth muscle hypertrophies in a newborn infant.

Transient neonatal myasthenia gravis is a rare disease; it affects an estimated 15% of all babies born to myasthenic mothers. Since the condition was first described by Strickroot, Schaeffer, and Bergo (1942), reports have appeared in English of 42 patients, 4 of whom died in the neonatal period. Intestinal smooth muscle hypertrophy is extremely rare in infancy and childhood; to our knowledge only 2 cases have been recorded (Pritchard and Hillier, 1920; Guthrie, 1945). We present a further case of intestinal smooth muscle hypertrophy in an infant dying soon after delivery from a myasthenic mother who had been treated with large doses of neostigmine throughout pregnancy. A possible relationship between the two is considered.