The Perinatal Adverse events and Special Trends in Cognitive Trajectory (PLASTICITY)- a prospective longitudinal follow-up cohort study.

This is a prospective follow-up cohort of initially 1196 subjects with predefined at-delivery risk factors out of 22,359 consecutive deliveries during 1971-74 at a single maternity hospital.

The subjects are now 40 - 43 yers of age.