Fetal limb soft tissue assessment for prediction of birth weight and umbilical cord blood analytes in gestational diabetes

Objective To evaluate the value of third trimester ultrasound (estimated fetal weight, cheek-to-cheek diameter, sectional Wharton's jelly area, sectional areas and fractional volumes in extremities) to predict birth weight and cord biochemical markers at birth (leptin, insulin, c-peptide, IGF1, erythropoietin and ferritin) in diabetic pregnancies. Method Prospective study in 49 patients with gestational diabetes. An ultrasound was performed between 32 and 34 weeks. Clinical data were collected, and a blood sample was obtained from cord after birth. ROC curve models were evaluated for 75th and 90th birth weight percentile. Univariate and multivariate models were used to assess the association between ultrasound and neonatal outcomes. Results Sectional areas and fractional volumes showed significant differences and highest AUC values for predicting birth weight. A significant association was found for extremities measurements with total birth weight and its percentile. The only marker which showed a significant association to estimated fetal weight was erythropoietin. Sectional areas and fractional volumes related to cord leptin, erythropoietin, insulin and c-peptide. Conclusion Sectional areas and fractional volumes improve the predictive value of estimated fetal weight in diabetic pregnancies. They also show a predictive association to biochemical changes in cord (leptin, insulin and erythropoietin) related to increased adiposity and risk of fetal hypoxia. © 2015 John Wiley & Sons, Ltd.