Objective: Evidence that mothers report higher levels of drinking retrospectively than during pregnancy has led some investigators to suggest that women systematically underreport alcohol antenatally and that alcohol-related deficits may actually reflect heavier prenatal exposure. This study is the first to compare the validity of antenatal and retrospective reports of pregnancy drinking, drug use, and smoking in relation to effects on infant neurobehavioral outcomes.
Methodology: Three hundred fifty-four inner-city mothers were interviewed regarding their alcohol, drug use, and smoking during pregnancy and retrospectively at 13 months' postpartum. Their infants were assessed at 6.5, 12, and 13 months on a large battery of neurobehavioral assessments.
Results: Although higher levels of alcohol were reported retrospectively, the correlations of prenatal alcohol exposure with infant outcome were as strong or stronger for the antenatal measures and only the antenatal reports predicted poorer cognitive performance on the Bayley Scales and symbolic play, slower processing speed on the Fagan Test of Infant Intelligence and cross-modal transfer, and slower infant reaction time. Women also reported higher levels of cocaine and marijuana but not cigarette smoking retrospectively. Relations between cocaine use and smoking on birth size and gestational age were as strong for either report. No effects were detected in relation to either report of marijuana use during pregnancy.
Conclusions: These findings suggest that antenatal alcohol interviews provide the most valid information and demonstrate the importance of assessing prenatal alcohol use during pregnancy to minimize the risk of failing to detect neurobehavioral deficits. Adverse effects were consistently seen at levels as low as 0.5 oz absolute alcohol/day (the equivalent of 7 drinks per week) based on maternal antenatal report. These data suggest that alcohol-related deficits do not reflect heavier prenatal exposure than that reported during pregnancy and that threshold values derived from antenatal reports are reasonably accurate.