Controversy exists whether carbohydrate-deficient transferrin (CDT) is valuable as a screening tool for fetal alcohol syndrome. We evaluated serum CDT in 60 non-alcohol-abusing women at different stages of normal pregnancy. CDT was weakly related to week of pregnancy and to human placental lactogen. CDT did not correlate with iron oestradiol or progesterone. By contrast, good correlations were found between transferrin and week of pregnancy or either sex hormone. Using multiple linear regression analysis, only transferrin and week of pregnancy were important predictors of CDT. The diagnostic accuracy of CDT for detecting alcohol abuse may be limited in pregnant women and should be carefully assessed in relation to alcohol consumption.