OBJECTIVE: We used ultrasound to measure fetal subcutaneous fat in pregnancies with normal and abnormal glucose tolerance tests (GTT).STUDY DESIGN: Thirty-five women with singleton pregnancies between 24 and 26 weeks' gestation participated in our study. We measured fetal subcutaneous fat tissue thickness in 20 women with abnormal GTT (Group A, study group) and 15 women with normal GTT (Group B, control group). Maximum subcutaneous fat tissue thickness of the fetuses was measured at three different levels of the fetal body, from the inner to the outer aspect of the echogenic subcutaneous fat. One measurement was taken at the level of the biparietal diameter (BPD), a second at the level of the abdominal circumference (AC) and the third was performed sagittally at the level of the thoracic spine (TS).RESULTS: Each variable was tested separately for statistically significant differences between the two groups using two statistical tests, the parametric Student's t-test and the non-parametric Mann-Whitney (M-W) test. Both tests verified a statistically significant difference for the three variables of interest (HC, AC and TS) between the two groups. Receiver Operating Characteristic (ROC) curves were used to determine the diagnostic value of each of the three variables regarding the detection of gestational diabetes. Finally, all three variables were used to construct a linear discriminant analysis model in order to evaluate their combined discrimination ability.CONCLUSION: Assessing these parameters using a noninvasive tool such as ultrasound could enhance the detection of gestational diabetes and limit the potential morbidity resulting from undiagnosed gestational diabetes. It could be useful in women who are unable to tolerate GTT or have poor follow-up during pregnancy.