Fetal Adrenal Gland Volume a Novel Predictor of Onset of Labor

Introduction: There is a definite need to find a highly sensitive and specific, noninvasive, and cost-effective marker for prediction of preterm labor. We hypothesize that a measurement of adrenal gland volume can predict a preterm as well as a term labor. Materials and Methods: Two hundred and sixty-eight pregnant women were enrolled in the study at 28–34 weeks’ antenatal visit. Final analysis was done in 204. All of them were subjected to 2D ultrasonographic measurement of the corrected fetal adrenal gland volume (cFAGV) and fetal adrenal zone parameters including the width ratio and depth ratio. The cohort was followed up to term, and a reassessment of cFAGV and fetal adrenal zone parameters was repeated between 37 and 39 weeks. Women who presented with features of preterm labor had a scan at the time of presentation to record cFAGV and fetal adrenal zone parameters. Results: Women, who developed features of preterm labor eventually, had a significantly high cFAGV (404.70 mm³/kg body weight) during the first scan compared to those who reached term asymptomatically (241.35 mm³/kg body weight). A cutoff value of 271.16 mm³/kg body weight showed 90% sensitivity and 81.9% specificity. Fetal adrenal gland width ratio had the best efficacy (sensitivity 96.67%, specificity 86.2%) followed by cFAGV (sensitivity 96.67%, specificity 83%) for predicting preterm delivery. Conclusion: 2D ultrasound measurement of fetal adrenal gland parameters can be used as a marker for prediction of preterm delivery. cFAGV at term can also be used to predict the possibility of spontaneous onset of labor.