The value of first trimester inflammatory indices in predicting the development of preeclampsia in the third trimester

Sahin et al. BMC Pregnancy and Childbirth (2025) 25:713 https://doi.org/10.1186/s12884-025-07836-1 BMC Pregnancy and Childbirth Open Access RESEARCH The value of first trimester inflammatory indices in predicting the development of preeclampsia in the third trimester Refaettin Sahin1* , Cem Inceoglu1 and Veysel Tahiroglu1,2 Abstract Objective This study aimed to evaluate the predictive value of hematologic inflammatory markers measured during the first trimester for developing preeclampsia in the third trimester. Methods This retrospective study included 192 pregnant women diagnosed with preeclampsia and 159 healthy pregnant women who presented to the Obstetrics and Gynecology Clinic of Sİrnak State Hospital between March 2024 and March 2025. Demographic data, obstetric history, and laboratory results were retrospectively analyzed. Inflammatory markers derived from complete blood count parameters—including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), and aggregate index of systemic inflammation (AISI)—were compared between the two groups. Results The mean age in the preeclampsia group was significantly higher (p = 0.002), while gestational age at delivery and birth weight were significantly lower (p < 0.001). Levels of hemoglobin, hematocrit, white blood cell count, and inflammatory markers such as NLR, SII, SIRI, and AISI were significantly lower in the preeclampsia group (p < 0.05). Monocyte counts were also significantly lower (p < 0.05). No statistically significant differences were observed between the groups regarding PLR and LMR. Conclusion Certain hematological inflammatory markers measured in the first trimester may serve as potential biomarkers for predicting the development of preeclampsia. Incorporating these markers into routine prenatal follow-up could contribute to the early identification of high-risk pregnancies. Trial registration This study was not registered in a trial registry as it is a retrospective observational study involving analysis of previously collected data. Keywords Preeclampsia, Inflammatory markers, Systemic immune-inflammation index (SII), Neutrophil-tolymphocyte ratio (NLR), Platelet-to-lymphocyte ratio (PLR), Maternal outcomes *Correspondence: Refaettin Sahin 1 Department of Obstetrics and Gynecology, Sirnak State Hospital, Sirnak, Turkey 2 Faculty of Health Sciences, Department of Nursing, Sirnak University, Sirnak, Turkey © The Author(s) 2025. 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To view a copy of this licence, visit http://creati vecommons.org/licenses/by-nc-nd/4.0/. Sahin et al. BMC Pregnancy and Childbirth (2025) 25:713 Introduction Preeclampsia is a common pregnancy complication characterized by new-onset hypertension with either proteinuria or end-organ dysfunction after 20 weeks of gestation [1]. It affects approximately 2–8% of all pregnancies worldwide and remains one of the leading causes of maternal and perinatal morbidity and mortality [1]. Although the exact pathogenesis of preeclampsia is not fully understood, placental ischemia, endothelial dysfunction, and systemic inflammation are considered major contributing factors [2]. Inadequate remodeling of the spiral arteries is thought to impair placental perfusion, leading to hypoxia, oxidative stress, and the increased release of anti-angiogenic factors [3]. These pathophysiological changes result in clinical manifestations such as hypertension, proteinuria, and other signs of organ dysfunction [4]. Genetic predisposition, immune system dysregulation, and environmental factors may also contribute to the development of the disease [5]. Recent studies have highlighted the central role of systemic inflammation in the development of preeclampsia. Hematologic inflammatory indices—such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), and pan-immuneinflammation value (PIV)—have attracted attention as accessible and cost-effective biomarkers for predicting preeclampsia [6]. Although the clinical manifestations of preeclampsia typically appear in the later stages of pregnancy, it is well established that the underlying pathophysiologic processes begin much earlier. Therefore, analyzing laboratory data from the first trimester may be valuable for identifying high-risk pregnancies and initiating early interventions. However, the existing literature in this area remains limited and includes some contradictory findings [7]. This study aimed to investigate whether first-trimester hematological inflammatory markers could predict the subsequent development of preeclampsia and to contribute to the limited body of literature on this topic by identifying easily obtainable, potential early biomarkers for use in routine clinical practice. Materials and methods This retrospective study was conducted at the Obstetrics and Gynecology Clinic of Sirnak State Hospital between March 2024 and March 2025. Ethical approval was obtained from the Sirnak University Ethics Committee (Approval No: E-74546226-050.04-130513), and the study was carried out in accordance with the Declaration of Helsinki. Page 2 of 6 The study population consisted of pregnant women who underwent complete blood count (CBC) analysis during the first trimester and delivered in the third trimester. Data were retrospectively retrieved from the hospital’s electronic medical records and included demographic characteristics, obstetric history, laboratory findings, and delivery outcomes. A total of 351 pregnant women met the inclusion criteria. Of these, 192 were diagnosed with preeclampsia based on the 2020 diagnostic criteria of the American College of Obstetricians and Gynecologists (ACOG) [1], while 159 women with uneventful pregnancies constituted the control group. Patients with chronic illnesses, autoimmune diseases, infectious c (...truncated)