Purpose: The aim of this study was to investigate whether the systemic immune-inflammatory index (SII) could predict the development of preterm labor in pregnant women. Materials and Methods: Pregnant women aged 18 years and over who presented to our clinic with spontaneous labor between January 1, 2018, and December 31, 2021, had intact membranes, and had a single living fetus were retrospectively evaluated. The women were divided into two groups, preterm and term delivery, according to the week of delivery. The clinical and laboratory characteristics of the women were assessed. The patients’ platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and SII (neutrophil count x platelet count/lymphocyte count) were calculated. Results: The study included 171 women with preterm labor and 173 women with healthy term labor. The PLR, NLR, and SII values were statistically significantly higher in the preterm group than in the term group. The multivariate logistic regression analysis showed that SII (odds ratio [OR]: 3.65, 95% confidence interval [CI]: 2.21–10.07) was an independent predictor of the development of preterm labor. We found that the power of SII to predict preterm labor (area under the curve [AUC]: 0.792) was higher than that of NLR (AUC: 0.725) or PLR (AUC: 0.716) alone. SII values higher than 789.3 predicted preterm labor with 68.4% sensitivity and 81.5% specificity. Conclusion: We found that SII was more valuable than NLR and PLR in the early detection of preterm labor. SII can help identify pregnant women at risk of developing preterm labor in the early stages of pregnancy.

Background: We aimed to predict the efficacy of the systemic immune-inflammatory index (SII) in predicting missed abortions. Methods: In this retrospective study, we analyzed the data of women diagnosed with a missed abortion between gestational weeks 7–12 at our clinic from January 2018 to December 2021. The control group consisted of women in healthy pregnancies who were at the same gestational weeks. The demographic characteristics of participants, SII (neutrophil count x platelet count/lymphocyte count), platelet-lymphocyte ratio (PLR), and neutrophil-lymphocyte ratio (NLR) values were evaluated in both groups. Results: A total of 142 missed abortion group and 142 control group were included. SII was found to be statistically significantly higher in the missed abortion group than in the control group (917.1 ± 549.7 and 557.1 ± 193.7, respectively; p < 0.001). In the logistic regression model, SII was found to be an independent predictor of a missed abortion (odds ratio = 2.85, 95% confidence interval: 1.34–4.15, p < 0.001). We found that the diagnostic value of SII (area under the curve [AUC]: 0.765) was higher than PLR (AUC: 0.711) or NLR (AUC: 0.703) alone in patients with a missed abortion. We determined that an SII value of >709.75 predicted the development of a missed abortion with 64.0% sensitivity and 80.9% specificity. Discussion: In recent years, complete blood count parameters have been increasingly used as an indicator of systemic inflammation. Although there are many studies in the literature investigating the relationship of a missed abortion with PLR and NLR, there is limited research evaluating the relationship of this clinical condition with SII. We determined that SII obtained from the combination of lymphocyte, platelet, and neutrophil counts was more valuable than evaluating these parameters by dividing them separately. Conclusion: Our results show that there is a significant relationship between SII and a missed abortion, and therefore SII can be used as a predictive marker of this clinical condition.

Purpose: The purpose of this study was to investigate a possible relationship between systemic inflammatory markers such as neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), lymphocyte monocyte ratio (LMR), threatened preterm labor (TPL), and preterm premature rupture of membranes (PPROM), using complete blood cell count (CBC) parameters. Method: The study was carried out prospectively with patients admitted to our university hospital due to preterm labor and at risk of PPROM. The cases were divided into three groups according to their pregnancy status. Group 1 consisted of 90 patients with PPROM between 24th and 36th gestational weeks; group 2, 115 patients diagnosed with TPL between 24th and 36th gestational weeks; group 3, 101 patients over 36 weeks of gestation (control) who were not in labor. In addition to the demographic data of the patients, CBC parameters (white blood cell (WBC), Hg, Hct, Plt, lymphocyte, monocyte, mean platelet volume, PLR, LMR, and NLR) and C-reactive protein (CRP) values were examined and compared in each of the three groups. Results: CRP and WBC values of group 1 (PPROM) were higher than group 2 (TPL) and group 3 (control) (p < 0.05 for both). Pearson correlation between the gestational age and PLR and NLR values was significant (r and p values for PLR and NLR, respectively, r = −0.18, p < 0.001; r = −0.23, p < 0.001). However, there was no significant difference between the groups regarding PLR, NLR, LMR, platelet, monocytes, and lymphocyte counts. Conclusions: Only WBC was a valuable parameter in predicting preterm labor and PPROM. Although there was no significant difference between the groups in PLR and NLR, a negative correlation was found with gestational age at delivery. CRP value is still a helpful parameter in PPROM and TPL prediction.