Neonatal myasthenia occurs in about 12% of babies whose mother has myasthenia gravis. Neonatal myasthenia gravis is caused by

Transient neonatal autoimmune diseases are seen due to the transplacental transfer of maternal IgG autoantibodies in those diseases in which IgG is the effector component of the autoimmune response. The disease will be of the same type as seen in the mother because the autoantibodies will determine the target organ specificity. The neonatal disease resolves after a few weeks as the maternal IgG is catabolised.