Trends, perinatal characteristics, and medical conditions in pervasive developmental disorders.

Our aim was to study trends in the prevalence of pervasive developmental disorders (PDD) and to quantify their association with morphogenetic anomalies and with perinatal characteristics such as gestational age, birthweight, and hospitalization in a neonatal care unit. Data from a French morbidity register of childhood disabilities with the use of consistent definitions over time within the same geographical area were analyzed. The data of a total of 454 children (312 males, 142 females) with PDD, born between 1980 and 1993 and residing in Isère county, were recorded at the age of 7 years. The overall prevalence of PDD was 22.2 out of every 10000. There was a significant increase, from 14.7 to 30.8 out of every 10 000, during the period of study. Among these children with PDD, morphogenetic anomalies were observed in 12.1% (95% confidence interval [CI] 9.3-15.5), and the hospitalization rate during the neonatal period was 22% (95% CI 17.0-27.5), which is significantly higher than the observed rates in the general population. The increase in the prevalence of PDD, the association with perinatal risk factors, and the high rate of neonatal hospitalization require further studies to investigate the reasons for and mechanisms of these developmental disorders.