Binge alcohol exposure during all three trimesters alters bone strength and growth in fetal sheep.

Women who drink while pregnant are at a high risk of giving birth to children with neurodevelopmental disorders. Heavy consumption of alcohol during pregnancy is also known to be deleterious to fetal bone growth in both humans and laboratory animals. However, nothing is known regarding the effect of maternal moderate and heavy alcohol binging on fetal and maternal bone strength. The purpose of this study was to determine the effects of moderate and heavy alcohol binging throughout gestation on fetal and maternal bone growth and strength. The study was conducted using an ovine model system. The large body mass of the ovine fetus, the longer gestation that is more similar to that of humans, and the fact that all three trimester equivalents occur in utero, make the sheep an excellent model for studying Fetal Alcohol Spectrum Disorder. Suffolk ewes were mated and, beginning on gestational day 4, received intravenous infusions over 1 h on 3 consecutive days per week followed by 4 days without treatment concluding on day 132 of pregnancy. Pregnant ewes were divided into four groups: two alcohol treatment groups (0.75 and 1.75 g/kg of body weight), one pair-fed saline control group, and an untreated normal control group. The fetuses were harvested on gestational day 133. Maternal and fetal femoral and tibial dimensions were measured and the maximum strength (MPa) carried by the bone tissue was determined using a three-point bending procedure. Maternal bones were not different among groups. The higher alcohol dose resulted in reduced fetal femoral bone strength, whereas the tibial bone strength was lower when compared with the normal control subjects. In contrast, the lower alcohol dose increased fetal femoral strength compared to the normal control subjects. The alcohol-exposed fetal bones also tended to exhibit reduced lengths. We conclude that binge alcohol exposure throughout gestation resulted in dose-dependent differences in the maximum stress absorbed by the fetal bones.