Developmental delay in congenital myotonic dystrophy after neonatal intensive care.

Six infants with congenital myotonic dystrophy survived after neonatal intensive care. In later childhood they were assessed by the Griffiths Mental Development Scales: five children were functioning in the mildly handicapped to borderline range of development (DQ 64.0 to 79.0) and the remaining child was severely delayed in development (DQ 33.0). The five children with higher DQ values had a history of ventilatory support of 30 days or less after birth. By contrast, the remaining child with the lowest DQ value had been ventilated for 43 days. This study provides further evidence that prolonged ventilation after birth has prognostic significance in identifying severely affected cases with congenital myotonic dystrophy.