Noninvasive assessment of classic and high PPROM using cervicovaginal podocalyxin and nephrin: Findings from a prospective observational study

This study assesses the diagnostic and prognostic value of cervicovaginal amniotic fluid (CVAF) podocalyxin (PDX) and nephrin levels in pregnancies with classic and high preterm premature rupture of membranes (PPROM), focusing on neonatal outcomes. This prospective study included 144 singleton pregnancies between 22 and 34 weeks, classified as classic PPROM (n = 74), high PPROM (n = 32), and controls (n = 38). CVAF and serum samples were analyzed using enzyme-linked immunosorbent assay to quantify PDX and nephrin levels. Receiver operating characteristic curves evaluated diagnostic performance. Logistic regression identified predictors of respiratory distress syndrome and bronchopulmonary dysplasia. CVAF PDX and nephrin levels were significantly higher in the classic PPROM group (35.05 ± 5.55 and 12.88 ± 3.85 ng/mL, respectively) compared to high PPROM and control groups. Receiver operating characteristic analysis demonstrated excellent diagnostic performance for distinguishing classic PPROM, with area under the curve values of 0.92 (95% confidence interval [CI]: 0.88-0.96) for PDX and 0.93 (95% CI: 0.89-0.97) for nephrin. In multivariable logistic regression, elevated PDX was independently associated with bronchopulmonary dysplasia (odds ratio = 1.32, 95% CI: 1.10-1.59), while elevated nephrin predicted respiratory distress syndrome (odds ratio = 1.18, 95% CI: 1.02-1.36). These findings support their utility as noninvasive biomarkers for both diagnosis and risk stratification in PPROM. CVAF PDX and nephrin demonstrated significant diagnostic and prognostic value in differentiating PPROM subtypes and may be useful for neonatal risk stratification. These findings suggest that CVAF PDX and nephrin levels may serve as noninvasive tools for early identification of high-risk PPROM cases, potentially guiding timely intervention and targeted neonatal care.