Background:Preterm birth is a multifactorial problem with a confounding management. Latent interval (Time to delivery) always shows wide variation and presence of a valid, reliable and applicable predictor is a controversial issue.  Objectives: to evaluate the role of fetal adrenal biometry (corrected-total gland volume c-TGV and fetal zone enlargement FZE), cervical length and IL17 serum level (maternal inflammatory biomarker) in prediction of preterm that could help in proper management and decreased morbidities.  Patient and Methods: Observational comparative study for 100 case (28 to 36 weeks gestation) showing clinical signs of threatened preterm labor. Corrected fetal adrenal gland volume, fetal zone enlargement, cervical length and IL17 serum level were measured then all candidates were followed up till delivery to classify the results into two groups according to the (latent interval). Diagnostic performance for all variables was done to detect the best cutoff value that can predict impending preterm delivery within 7 days using univariate analysis and receiver operating characteristic (ROC) curve.  Results: The studied predictors were showing best cutoff, sensitivity%, specificity% and accuracy% as follow: c-TGV (≥400 mm³/kg, 80, 75, 85), FZE(≥ 50%, 90, 80, 92), cervical length (≤16 mm, 70, 67, 65), IL17 serum level (8 pg/ml, 80, 95, 83) respectively. Conclusion Utility of corrected fetal adrenal gland volume, fetal zone enlargement in addition to the IL17 (inflammatory marker) as a non-invasive predictors for impending preterm birth can guide a proper decision.