Arthrogryposis multiplex in a newborn of a myasthenic mother--case report and literature.

About 12% of children of myasthenic mothers exhibit a transitory myasthenic syndrome. Usually, these symptoms have disappeared after a few weeks. Treatment with anticholinesterase drugs is successful. The purpose of this paper is to present an infant born to a myasthenic mother, with distal arthrogryposis, severe hypotonia and respiratory distress, unresponsive to administration of pyridostigmine bromide. Eleven other cases of neonatal myasthenia with arthrogryposis are known. Five of them were stillborn or died within the first day of life. The surviving children had profound weakness and needed ventilatory assistance for a long period. The severity of these few cases contrasts with the numerous reports of benign and transitory signs of neonatal myasthenia. Passively transferred maternal acetylcholine receptor antibodies may produce illness in the newborn.