obstetric complications and age at onset in schizophrenia: an international collaborative meta-analysis of individual patient data

Data from 854 schizophrenic patients concerning history of obstetric complications, rated according the Lewis and Murray scale, were obtained from 11 different research groups. Subjects with onset of schizophrenia before age 22 were 2.7 times more likely than those with onset at a later age to have had a history of abnormal presentation at birth and 10 times more likely to have had a history of complicated cesarean birth.