Assessment of fetal adrenal gland and thymothoracic ratio in preterm premature membrane rupture: a prospective case-control study

Objectives This study aims to investigate the role of fetal thymus and adrenal medulla dimensions in the pathogenesis of preterm prelabor rupture of membranes (PPROM). Methods A prospective, case-control study was conducted involving 45 pregnant women with PPROM between 28 and 37 weeks of gestation and 45 matched healthy controls. Ultrasonographic measurements of fetal thymus (width, length, TTR) and adrenal glands (length, width, depth, volume), including the adrenal medulla, were performed. Biochemical markers (WBC, CRP) and neonatal outcomes were recorded. Statistical analyses included comparisons between groups, correlation assessments, and ROC curve analysis to evaluate predictive parameters. Results The fetal thymus dimensions and TTR ratio were significantly smaller in the PPROM group. The adrenal medulla volume, length, and depth were notably reduced, while total adrenal gland size showed no significant difference. Moderate negative correlations were observed between inflammatory markers and TTR. ROC analysis indicated that TTR and adrenal medulla volume could predict NICU admission with moderate sensitivity and specificity. Conclusions The findings suggest that alterations in fetal thymus and adrenal medulla sizes are associated with PPROM and may serve as potential biomarkers for its diagnosis and prognosis. Further large-scale studies are warranted to validate these parameters and explore their clinical applications.