Pre- and perinatal factors and the risk of subsequent referral for hyperactivity.

Possible pre- and perinatal risk factors for subsequent referral for hyperactivity were assessed by comparing birth records of 129 referrals with the remaining 24,656 members of a geographically defined birth cohort. Relationships between the risk factors were accounted for using logistic regression methods. The significant factors were: social class, maternal age, antepartum haemorrhage, length of labour (second stage), 1-min Apgar and sex. Associations between referral for hyperactivity and the pregnancy, labour and birth outcome factors were not explained by the socio-demographic variables. The results suggest that such factors have a statistically significant association with referral for hyperactivity and may be of modest aetiological importance. However, the predictive power of the final set of factors remained low even on the original data set.