Inflammatory, Immuno-Nutritional, and Composite Stress Indices in Previable Preterm Premature Rupture of Membranes

To evaluate inflammatory, immuno-nutritional, and composite stress indices derived from routine laboratory parameters in pregnancies complicated by previable preterm premature rupture of membranes (PPROM) and compare these with gestational age-matched healthy controls.

This retrospective cohort included 50 women with previable PPROM before 22 weeks and 50 gestational age-matched controls. Hematological and biochemical parameters obtained within 24 hours of admission were used to calculate neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), systemic immune-inflammation index (SII), white blood cell-to-albumin ratio (WAR), neutrophil-to-albumin ratio (NAR), neutrophil-to-lymphocyte-to-albumin ratio (NLAR), lymphocyte-to-albumin ratio (LAR), platelet-to-albumin ratio (PAR), platelet-to-lymphocyte ratio (PLR), and hemoglobin-to-albumin ratio (HAR). In addition, a novel hemato-immuno-nutritional impairment index (HINI) and newly proposed composite stress-reserve indices-composite stress index (CSI), inflammation-over-reserve index (IORI), thrombo-hemoglobin composite index (THCI), and global composite systemic index (GCSI)-were evaluated. Statistical comparisons, age-adjusted logistic regression, and receiver operating characteristic analysis were performed.

In age-adjusted logistic regression analyses, only NLR, dNLR, SII, WAR, NAR, NLAR, CSI, IORI, and GCSI remained independently associated with PPROM, whereas other evaluated indices did not retain statistical significance. Receiver operating characteristic analysis demonstrated the strongest discriminatory performance for NAR, NLAR, and IORI.

Previable PPROM is characterized by acute neutrophil-dominant inflammation. Combined indices integrating inflammatory activity with physiological reserve, especially NAR, NLAR, and IORI, may improve early identification of affected pregnancies.