Maternal recall of pregnancy history: Accuracy and bias in schizophrenia research

Most investigations that report a positive association between obstetric co mplications and schizophrenia have been case-control studies that are often based on long-term maternal recall of events during pregnancy. We tested t he hypothesis that mothers of adult offspring with schizophrenia or other p sychoses systematically overreport obstetric complications compared with mo thers of unaffected offspring. Subjects were selected from the New England cohorts of the National Collaborative Perinatal Project, a large prospectiv e cohort with well-documented records of pregnancy and delivery, Mothers of 39 offspring with psychosis and 39 control offspring were recontacted and completed a structured interview regarding their pregnancy history. Accurac y of maternal recall varied greatly in relation to the type of pregnancy ev ent, and recall was inaccurate for many specific events. For the control sa mple only, maternal recall of the total number of complications corresponde d closely to chart information. Contrary to the study hypothesis, mothers o f offspring with psychosis report fewer complications than indicated in the ir obstetric records, with no evidence of positive recall bias. These resul ts suggest that previous reports of a positive association between obstetri c complications and schizophrenia are not likely to have resulted from bias ed maternal recall.