Validation of maternal self-report in retrospective studies.

Case-control studies are frequently performed in prenatal and perinatal epidemiology. For data collection, these studies often rely on self-administered questionnaires or personal interviews. Although of importance, validation of these measurement instruments received little attention in epidemiologic research so far. In this letter, we stress the need for more well-conducted validation studies in the field of prenatal and perinatal epidemiology. In addition, we comment on a validation study that was previously published in this journal.