Distal tibial trabecular morphometry in a Sprague Dawley rat model of fetal alcohol syndrome: a micro focus X-ray computed tomography case-control study

Abstract

Introduction: intrauterine alcohol exposure has adverse health effects on the offspring, which may result in fetal Alcohol Spectrum Disorders (FASD). The neurological and craniofacial aspects have been well studied; however, long bones have received limited attention despite the short stature reported in FASD children.

Methods: time-mated (n=13) pregnant Sprague Dawley dams were assigned to either the ethanol (n=5), saline control (n=5) or untreated group (n=3) which received no treatment. The ethanol and saline control dams were treated with 0.015ml/g of 25.2% ethanol or 0.9% saline, respectively. Treatment was for the first 19 days of gestation. Two pups from each dam were used and terminated at 21 days of age. Paired tibiae were harvested. Each bone was scanned using a Nikon XTH 225L 3D-μCT to investigate trabeculae morphometry.

Results: the ethanol group had less bone to total volume (BT/TV), thinnest trabeculae (TbTh) which were less spaced (TbSp) compared to the controls. However, number of trabecular (TbN) remained unaffected in all three groups. Tibial length was similar in all three groups; however, the distal metaphysis volume was smallest in the ethanol group. Logistic regression showed that distal trabecular separation was the main parameter affected the most in gestational alcohol in the tibia. The negative correlation of trabecular thickness and spacing in the ethanol group may be a contributor to bone weakness.

Conclusion: gestational alcohol exposure affects bone internal morphology in addition to the bone size. Overall, this study supports the findings clinical observation of small stature in FAS children.