Objective: Obstetric complications may be an etiologically important factor in the development of schizophrenia. The aim of this study was to evaluate whether the risk for developing schizophrenia in adult life is increased in individuals with more severe obstetric complications at birth.
Methods: To this end, mothers were interviewed to gather data about obstetric complications. The 'midwife protocol' of Parnas and colleagues was used to quantify the presence and entity of obstetric complications. We studied the frequency distribution and the severity of obstetric complications in 64 male DSM IV schizophrenic patients. The genetic load was reduced by using 81 brothers who were not psychiatric patients as controls. Odds ratios for the effects of obstetric complications, maternal age, birth order and birth weight were calculated using conditional logistic regression.
Results: The only factor found to have a significant effect on the risk of schizophrenia was the overall measure of obstetric complications at birth. The history of obstetric complications was higher in schizophrenic patients than in their siblings.
Conclusion: The results seem to confirm the hypothesis that obstetric complications may contribute to increased vulnerability to the disease, in addition to genetic risk factors.