Obstetric Complications: A Reappraisal

Abstract

It is well known that there have been many reports in the last 20 years that the incidence of obstetric complications is higher in people who subsequently develop schizophrenic illnesses than in their sibs or matched controls. Geddes & Lawrie (1995) carried out a meta-analysis of 20 case control and 2 cohort studies, covering a total of 1000 schizophrenic subjects, and showed that on average obstetric complications were twice as common in the schizophrenics as in their controls. It is still unclear, though, which individual complications of pregnancy or delivery are risk factors for schizophrenia, partly because the evidence is conflicting, but mainly because most case control studies were based on such small numbers that they had to use a single composite index of obstetric complications. Even so, it is widely assumed that obstetric events contribute to the aetiology of schizophrenia and that the pathogenic agent is anoxic damage to the fetal brain either in late pregnancy or at the time of delivery.