The potential role of high or low birthweight as risk factor for adult schizophrenia

Objective: Obstetric complications may be an important factor in the development of schizophrenia. The aim of this study is to evaluate the role of these complications in the development of schizophrenia in adult life, with particular attention to the potential role of birth weight. Method: We carried out a case-control study, comprising schizophrenics and patients with diseases of the schizophrenia spectrum as cases, and their healthy male brothers as controls. Obstetric complications were assessed using the "Midwife Protocol" of Parnas et al. Results: The main result was that birth weight may be a risk factor for schizophrenia, as indicated by odds ratio analysis. The confidence intervals are very wide and, without compromising the clinical significance of the results, they give a limited indication of the real entity of the risk. Conclusions: The results contribute to understanding of the role played by a single complications.