P94: Disorders of muscle tone of newborn

P94.0: Transient neonatal myasthenia gravis

Muscle movement is controlled by nerves. For information to get from the nerves to the muscles, nerve cells generate certain signals. These signals are absorbed by the muscle cells.

When there is a particular muscle disorder, antibodies are produced in the body. These antibodies prevent the signal substances from being properly transmitted between the nerves and muscles. If the signal substances between the nerves and muscles are not being properly transmitted, the muscles may quickly weaken. If these antibodies are present in the mother's blood, they can get into the child's blood via the placenta. While in the womb, mother and child are connected to one another via the placenta.

If the mother's antibodies get into the child's blood, the child's muscles may get weaker. Shortly after the birth there can be various indications that the child has muscle weakness. The arms and legs may appear limp. The child may move about less than usual. It might also have a sucking weakness. It may also have breathing problems.