Neutrophil-to-lymphocyte ratio at admission helps to predict the need for blood transfusion after vaginal delivery.

OBJECTIVE

This study assesses the association between complete blood count (CBC) parameters, including the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) and predicts the need for postpartum packed red blood cell transfusion (pRBCT).

METHODS

This retrospective cohort study was conducted at a tertiary, university-affiliated medical center with approximately 12 500 annual deliveries (2012-2023). Women requiring postpartum pRBCT were identified based on criteria including severe hemorrhage, symptomatic anemia with hemoglobin (Hb) levels of 7-8 g/dL, or severe anemia (Hb <7 g/dL). Maternal demographics, admission complete blood count (CBC), and delivery outcomes were analyzed. Multivariable logistic regression identified independent predictors of pRBCT, and a risk score was developed and evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

Admission CBC data were available for 37 631 vaginal deliveries, of which 957 (2.5%) required pRBCT. Risk factors for pRBCT included nulliparity, previous cesarean, assisted reproductive technology conception and intrapartum fever. Protective factors included spontaneous labor onset, body mass index >30, and admission hematocrit >40%. Key CBC independent predictors included Hb <11 g/dL (adjusted odds ratio [aOR] 5.70, 95% confidence interval [CI] 4.79-6.79), and NLR >5 (aOR 1.28, 95% CI 1.02-1.60). The scoring model, with a clinical cutoff of 5, predicted pRBCT with an area under the curve of 0.77 (95% CI 0.75-0.79, P < 0.001).

CONCLUSION

Admission CBC parameters, particularly NLR and Hb, alongside maternal factors, might help predict pRBCT in vaginal deliveries.