Accuracy of retrospective reports of infections during pregnancy

A large body of research suggests a relationship between maternal influenza and the development of schizophrenia in the adult offspring. Some researchers, however, have questioned this association. A study by Crow and Done (1992) asserts that prenatal exposure to influenza does not cause schizophrenia. The methodology employed by Crow and Done may account for their null findings. Crow and colleagues assessed influenza by asking mothers at the time of birth to recall influenza infections experienced during pregnancy. Such retrospective recall may bias reporting. We assessed influenza symptoms during pregnancy in a group of 136 mothers at the twenty-fifth week of pregnancy, and again one or two days after birth. We compared accounts of influenza at the twenty-fifth week to recollection of influenza after birth. Results suggest that mothers tend to under-report infections when recalling infections after birth. Retrospective assessment of influenza symptoms at birth may be an inaccurate method of assessing influenza during pregnancy.