Clinical and laboratory factors associated with placental abruption: a retrospective case-control study

Aims: Placental abruption (PA) is a major obstetric emergency associated with substantial maternal and neonatal morbidity and mortality. Although systemic inflammation and vascular dysfunction have been implicated in its pathophysiology, the clinical and laboratory factors associated with PA remain incompletely characterized. In this study, we aimed to investigate the relationship between PA and first-trimester and preoperative laboratory parameters, along with selected clinical features. Methods: This retrospective case control study included 308 singleton pregnancies, comprising 59 women with PA and 249 controls. Maternal demographic characteristics, obstetric variables, laboratory parameters, hemodynamic measurements, and maternal and perinatal outcomes were compared between groups. Factors independently associated with PA were identified using multivariable logistic regression analysis. Results: Compared with controls, females with PA had lower gestational age at delivery and neonatal birth weight (both p<0.001). Preoperative inflammatory markers, including leukocyte count, neutrophil count, and neutrophil-to-lymphocyte ratio (NLR), were significantly higher in the PA group (all p<0.05). Systolic, diastolic, and mean arterial pressures (MAP) were also higher in females with PA. Neonatal intensive care unit admission, perinatal mortality, and maternal transfusion rates were also significantly increased (all p<0.001). Multivariable logistic regression demonstrated that maternal age (odds ratio [OR]=0.866, 95% confidence interval [CI]: 0.789–0.951; p=0.003), gestational age (OR=0.648, 95% CI: 0.478–0.880; p=0.005), MAP (OR=1.096, 95% CI: 1.030–1.166; p=0.004), antepartum bleeding (OR=46.285, 95% CI: 16.132–132.802; p<0.001), and preoperative NLR (OR=1.329, 95% CI: 1.057–1.670; p=0.015) were independently associated with PA, whereas preoperative alanine aminotransferase was not significantly associated with PA (p=0.748). Conclusion: In conclusion, maternal age, gestational age, MAP, antepartum bleeding, and preoperative NLR are independently associated with PA. Owing to its low cost and widespread accessibility, NLR offers a practical supplementary marker when clinical suspicion of PA arises. Nevertheless, because post-presentation values may merely capture the acute inflammatory cascade triggered by the event itself, clinicians should exercise caution and avoid overinterpreting NLR as a predictive indicator pending well-designed prospective studies.