Maternal prenatal systemic inflammation indexes predicts premature neonatal respiratory distress syndrome

Neonatal respiratory distress syndrome (NRDS) is one of the leading causes of neonatal mortality in low-income countries. It is caused by a lack of surface-active substances in the lungs, and the maternal inflammatory response plays an important role in the formation of surface-active substances in the fetal lungs. We aimed to investigate the correlation between maternal prenatal systemic inflammatory indices and respiratory distress syndrome in preterm neonates. This is a retrospective case–control study that collected data from all patients who delivered between 28 and 36 weeks of gestation at Longhua District People's Hospital in Shenzhen City and whose infants were admitted to the neonatal unit, newborns with respiratory distress syndrome were in the experimental group (NRDS group), and newborns without NRDS were in the control group (non-NRDS group). To minimize the effect of confounders on the results, propensity score matching was performed on baseline characteristics. Totally, 524 patients were included (93 in the NRDS group and 431 in the non-NRDS group), and 71 matched pairs (142 patients). The neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), aggregate index of systemic inflammation (AISI) and neutrophil lymphocyte to platelet ratio (NLPR) were higher in the NRDS group than in the non-NRDS group (p < 0.05). The ROC curves of NLR, dNLR, SII, SIRI, AISI and NLPR for the diagnosis of NRDS were plotted, and it was found that the combined diagnostic efficacy of these six systemic inflammatory markers was better (AUC: 0.643, P = 0.003). Patients were divided into two groups based on the cut-off values determined from the ROC curves, and analysis using binary regression models revealed that SII ≥ 1199.94 (OR, 2.554; 95% CI 1.245–5.239, P = 0.011) and NLPR ≥ 0.0239 (OR, 2.175; 95% CI 1.061–4.459, P = 0.034) were independent risk factors predicting NRDS. Maternal prenatal SII ≥ 1199.94 and NLPR ≥ 0.0239 are independent risk factors for NRDS, and clinicians may be used to prevent neonatal respiratory distress in advance to reduce the incidence of NRDS.