First‐Trimester Hematologic Inflammatory Markers and Pregnancy Loss in Women With Unexplained Recurrent Pregnancy Loss: A Retrospective Study of Associations and Discrimination
Ruifang Wang, Fangxiang Mu, Wei Zhang, Kexin Wang, Fang WangABSTRACT
Objective
This study aims to investigate whether complete blood count (CBC)‐derived systemic inflammation indices are associated with pregnancy loss in women with unexplained recurrent pregnancy loss (URPL).
Methods
This retrospective observational study included 517 women with URPL who were recruited from Lanzhou University Second Hospital between September 2019 and December 2022. Participants were categorized into the pregnancy loss ( n = 265) group and live birth ( n = 252) group. CBCs obtained at 4–8 weeks of gestation were used to calculate the neutrophil‐to‐lymphocyte ratio (NLR), monocyte‐to‐lymphocyte ratio (MLR), platelet‐to‐lymphocyte ratio (PLR), systemic immune‐inflammation index (SII), and systemic inflammation response index (SIRI). We fitted multivariable logistic regression models adjusted for age, education, ethnicity, and body mass index. We assessed in‐sample discriminative performance using receiver operating characteristic (ROC) curves.
Results
Compared with the live birth group, the pregnancy loss group had higher neutrophil counts, NLR, SII, SIRI, MLR, and PLR, and lower lymphocyte counts (all p < 0.001). After adjustment, higher NLR (OR = 3.05, 95% CI: 2.25–4.21), SIRI (OR = 2.74, 95% CI: 1.77–4.33), and SII (per 100‐unit increase, OR = 1.36, 95% CI: 1.24–1.51) were associated with greater odds of pregnancy loss. In tertile analyses, compared with the lowest tertile, the highest tertile was associated with higher odds of pregnancy loss for NLR (OR = 5.51), SII (OR = 2.88), SIRI (OR = 2.55), MLR (OR = 2.41), and PLR (OR = 3.41), with all p ‐values for trend < 0.001. In ROC analyses, NLR showed the highest in‐sample discriminative performance (AUC = 0.752), followed by SII (AUC = 0.716).
Conclusion
First‐trimester CBC‐derived inflammatory indices, particularly NLR and SII, were associated with pregnancy loss in women with URPL and may have potential discriminative value within this cohort. These findings require confirmation in prospective, multicenter studies with broader confounder assessment and external validation before any clinical application can be considered.