Comparison of Histological Chorioamnionitis Findings Between Term and Preterm Deliveries

Background: This study aimed to determine the findings of histological chorioamnionitis (HCA) that may lead to preterm labor. Methods: A total of 126 women who underwent cesarean delivery at our hospital’s obstetrics clinic between May 1 and December 31, 2022, were prospectively included in the study (Group 1, Term labor, n = 63, Group 2, Preterm labor, n = 63). Participants’ sociodemographic characteristics, laboratory results, and histopathological findings were documented and compared between the groups. Placentas were examined for the diagnosis of HCA by a senior pathologist. Results: Significant differences were observed between Group 1 and Group 2 in gestational age at delivery (38.6 ± 1.3 vs 33.6 ± 1.6 weeks, respectively; p < 0.001), Apgar scores at the first minute (8.8 ± 0.6 vs 8.1 ± 1.8; p < 0.001), and neonatal intensive care unit (NICU) admission (9.5% vs 42.9%; p < 0.001). Although hemoglobin (Hb) levels, mean platelet volume (MPV), mean corpuscular volume (MCV), and lymphocyte, neutrophil, monocyte, platelet counts, as well as the pan-inflammatory value at admission, were comparable between groups (p > 0.05), leukocyte counts (10,382.54 ± 2020.58 vs 12,133.33 ± 4936.01, respectively; p = 0.011), neutrophil-lymphocyte ratio (4.21 ± 1.60 vs 5.46 ± 1.48; p = 0.040), and C-reactive protein (CRP) values (6.46 ± 5.56 vs 15.90 ± 9.27 g/dL; p = 0.027) differed significantly between the two groups. The incidence of acute (7.9% vs 49.2%), mild (33.3% vs 49.2%), and moderate (3.2% vs 14.3%) chorioamnionitis was statistically significantly higher in the preterm labor group (p < 0.05). Conclusions: The study findings show that the prevalence of HCA is notably higher in pregnant women with preterm deliveries, and that both the neutrophil-to-lymphocyte ratio and CRP levels are higher in preterm compared to term deliveries. Further studies with larger cohorts are warranted to elucidate these associations.