The Efficacy of C-Reactive Protein (CRP) to Albumin Ratio (CAR) and Fibrinogen to CRP Ratio (FCR) in Predicting the Latent Period of Preterm Labor

Objective

To investigate the role of inflammatory markers, including neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and monocyte to lymphocyte ratio (MLR), c-reactive protein (CRP) to albumin ratio (CAR), fibrinogen to albumin ratio (FAR), and fibrinogen to CRP ratio (FCR) in predicting the latency period (≤72 vs. >72 hours) before preterm birth.

Materials and Methods

In a retrospective study, we assessed 135 patients meeting the specified criteria with signs of preterm labor (<34 weeks). The patients were categorized into two groups: 71 patients giving birth within 72 h (latency ≤ 72 h) and 64 patients giving birth after 72 h (latency > 72 h). We examined the demographic and medical characteristics and perinatal outcomes of all participants. Categorical variables between groups were compared using the Chi-square test. The Student's t-test was utilized for normally distributed continuous variables, and the Mann–Whitney U test was applied for non-normally distributed data. Receiver operating characteristic (ROC) curve analysis was conducted to identify the optimal cut-off levels for inflammatory markers in predicting the latency period before birth.

Results

Among the parameters examined, significant differences were observed between the groups only in terms of CAR and FCR. While CAR showed a significantly higher value in the group with latency period ≤72 h (0.537 ± 1.239 vs. 0.247 ± 0.325, p = 0.022), FCR showed a significantly lower value in the group with latency period ≤72 h (63.58 (2.99–1165) vs. 88.93 (9.35–1165), p = 0.013). The identified cut-off value for CAR was 0.190, providing a sensitivity of 57.7% and a specificity of 56.3% (p = 0.022). The cut-off value for FCR was 71.67, with a sensitivity of 42.3% and a specificity of 42.2% (p = 0.013).

Conclusions

The CAR and the FCR, serving as predictive markers for preterm labor, may offer a simple, cost-effective, and easily accessible approach, particularly in resource-limited settings.