DIAGNOSTIC ACCURACY OF VAGINAL FLUID Β-HCG FOR PRELABOUR RUPTURE OF MEMBRANES IN A NIGERIAN TERTIARY HOSPITAL

ABSTRACT Pre-labour rupture of membranes (PROM) is a common obstetric complication with significant implications for maternal and neonatal health, particularly in low-resource settings. This study evaluated vaginal fluid β-human chorionic gonadotropin (β-HCG) as a diagnostic marker for pre-labour rupture of membranes (PROM) at Irrua Specialist Teaching Hospital, Nigeria. Using a prospective case-control design, we enrolled 200 pregnant women (2840 weeks gestation) classified into confirmed PROM (n=50), suspected PROM (n=50), and control (n=100) groups. Vaginal fluid β-HCG levels were measured using standard biochemical methods. Results showed a progressive increase in mean β-HCG from controls (32.13 ± 13.55 IU/ml) to suspected (135.84 ± 40.81 IU/ml) and confirmed PROM cases (424.98 ± 23.6 IU/ml; p<0.001). Receiver operating characteristic analysis demonstrated excellent diagnostic accuracy (AUC=0.971, 95% CI: 0.951-0.991), with optimal cutoff at 146.9 IU/ml (sensitivity=98.0%, specificity=87.8%). The test showed high predictive values (PPV=89.09%, NPV=97.78%) and strong likelihood ratios (LR+=7.97, LR-=0.20). Amniotic fluid index was significantly lower in confirmed PROM cases (9.17±1.72) versus controls (13.53±2.57; p<0.001). These findings confirm vaginal fluid β-HCG as a reliable, cost-effective diagnostic tool for PROM, particularly valuable in resource-limited settings where conventional methods are unavailable. Implementation could significantly improve diagnostic confidence and reduce adverse outcomes through timely intervention.