Decreasing gestational age and birthweight in spastic diplegia.

Over a 4-year period a significant fall occurred in the mean birthweight and mean gestational age of prematurely born children who subsequently developed spastic diplegia. This coincided with a considerable improvement in perinatal mortality in the unit in which they were delivered. However, although the number of premature deliveries remained stable, the disorder did not become less common. No specific aetiological factors were identified, but the 24 affected children frequently had a history of adverse prenatal or perinatal factors. We conclude that high standards of obstetric and neonatal care prevent the subsequent development of spastic diplegia in low birthweight infants. However, these factors have also improved the survival of very low birthweight infants who have a much higher risk for the disorder and this has prevented a significant reduction in its frequency.