A population-based study of mild mental handicap in children: preliminary analysis of obstetric associations

One hundred and twenty-nine children in the 8- to 12-year-old age group in Cardiff were ascertained to have mild mental deficiency. Detailed obstetric data were obtained which indicated that nearly 69% of the children were associated with adverse obstetric factors. Fifty-five per cent had the combined pathogenetic risk factors of pre-, peri- and neonatal adversities. Forty-two per cent of the cases had non-optimal perinatal factors and 45% were considered to have prenatal causation. There were four children with chromosomal anomalies. The various adverse obstetric influences are discussed separately.