The problem of obstetrical complications and schizophrenia.

The use of the term "obstetrical complications" (OCs) and its variations to encompass diverse physiological mechanisms (e.g., genetic, ischemic, hemorrhagic, infectious) of disruption to fetal/neonatal brain development has engendered inconsistency, confusion, and controversy. The principal reason is that the term OCs belies the absence of a fully adequate conceptual framework for characterizing neurodevelopmental risk. We propose that neurodevelopmental risk factors for schizophrenia can be assessed more clearly if broad OC scales are replaced by measures representing more homogeneous pathways of disturbed brain development. Using a new OC classification, we found that disordered growth related to hypoxic-ischemic compromise to early brain development may confer an elevated risk of schizophrenia and other adult-onset psychoses, particularly in the presence of familial risk. Abnormal fetal and neonatal brain growth and development in schizophrenia and OCs may also, at least in part, result from genetic factors and could help explain the relation between seemingly inconsistent OCs identified in prior research.