How does myotonic dystrophy affect pregnancy?

Women with type 1 myotonic dystrophy (DM1) are at increased risk for having a child with congenital myotonic dystrophy, a severe form of the disorder. Such babies are often surrounded in the uterus by excess amniotic fluid. A woman with DM1 may have a difficult delivery because she may experience weak uterine contractions or the baby may be in a breech position. No reports exist of a congenital form of type 2 myotonic dystrophy (DM2).