Comparison of Inflammatory Factors of Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Maternal Platelet Count in Patients with and without Chorioamnionitis and with Premature Preterm Rupture of Membrane

The present study aimed to compare inflammatory markers of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, and maternal platelet count in patients with and without chorioamnionitis with premature preterm rupture of membrane (PPROM).

Women with PPROM and gestational age less than 34 weeks were enrolled in this cohort study. PPROM was confirmed with sterile speculum examination or the AmniSure test. A blood sample was drawn from mothers for complete blood count (CBC) and differential count (Diff) before administering antibiotics and corticosteroids. Another blood sample was drawn for CBC-Diff tests at the time of pregnancy termination. The status of mothers and fetuses was carefully monitored during hospitalization through the following indicators: vital signs, daily abdominal examination, uterus discharge, daily non-stress test, and weekly ultrasonography. All samples were collected in one year.

A total of 110 patients were examined. The reason for pregnancy termination was gestational age of 34 weeks in 30 patients (27.3%), chorioamnionitis in 19 cases (17.3%), pain and dilation in 32 cases (29.1%), and miscellaneous in 29 cases (26.4%). Among the study parameters, only NLR was significantly different between groups, and the order of values from highest to lowest was in the chorioamnionitis, pain and dilatation, miscellaneous, and gestational age of 34 weeks groups. We found that NLR at a cut-off point of 3.2 - 3.5 had an acceptable sensitivity and low specificity to detect the cases of chorioamnionitis. Raised NLR was associated with (95% CI) histological chorioamnionitis with a sensitivity of 86% and a specificity of 43%.

According to the findings of our study, NLR can be a suitable indicator for predicting chorioamnionitis in women who deliver preterm without clinical signs and symptoms of infection. It can be used for expectant management for PPROM after 34 weeks.