Patterns of prenatal alcohol exposure and associated non-characteristic minor structural malformations: a prospective study

The characteristic facial features of the more severe end of Fetal Alcohol Spectrum Disorders (FASD) include smooth philtrum, thin vermillion of the upper lip, and short palpebral fissures. A systematic evaluation of a comprehensive list of minor structural defects in association with varying patterns of prenatal exposure to alcohol has not been performed. We examined the patterns and timing of prenatal alcohol exposure to minor structural malformations occurring in at least 5% of the sample. Patterns of drinking were evaluated by drinks per day, number of binge episodes, and maximum number of drinks. Timing of exposure was evaluated 0-6 weeks post-conception, 6-12 weeks post-conception, first trimester, second trimester, and third trimester. Naevus flammeus neonatorum is significantly associated with various patterns of drinking during the second half of the first trimester (RR 1.14, 95% CI 1.04, 1.24 for average number of drinks per day; RR 1.04, 95% CI 1.02, 1.07 for number of binge episodes; RR 1.08, 95% CI 1.01, 1.15 for maximum number of drinks in one episode) and similar for number of binge episodes in all categories of timing of exposure and in the second trimester for average number of drinks per day. Other minor malformations occurring in at least 5% of the sample were not found to be significantly associated with prenatal alcohol exposure. Expected minor malformations were not found to be significantly associated with prenatal alcohol exposure. Naevus flammeus neonatorum appears to be part of the spectrum of features associated with prenatal alcohol exposure.