Agreement between prospective and retrospective reports of maternal exposure to chemicals during pregnancy

As part of a prospective study of solvent exposure and child behavior, it occurred that women's responses about exposure history during pregnancy differed from the information documented during the postpartum period. The objective of the study was to examine the levels of agreement in 29 self-reports of exposure information obtained before and 3- to 7-years after pregnancy. Percent agreement was low for duration of exposure (41%), protective barrier use (48%), and symptomatology (41%). When reports were not in perfect agreement, women tended to report longer durations of exposure (r = 0.67), increased use of protective barriers (r = 0.39), and more symptoms at time of follow-up (r = 0.57). Agreement of report was not substantially associated with time since pregnancy or concurrent child behavior. Low levels of agreement may reflect response biases in the data collected at time of pregnancy or recall biases at time of follow -up. These variations in self-reports are of concern because they can severely affect estimates of human teratological risk.