Monocyte-to-lymphocyte ratio in the early second trimester is a predictor of gestational diabetes mellitus.

Objective: To evaluate neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), neutrophil-to-monocyte ratio (NMR), and other hemogram-derived inflammatory parameters measured in the early second trimester and their association with the risk of gestational diabetes mellitus (GDM).

Methods: This case-control study was conducted with 105 women with GDM and 205 healthy pregnant women, matched for maternal age at a 1:2 ratio with the cases at two regional maternity hospitals between January 2021 and August 2022. The inflammatory blood cell indices were tested in the early second trimester, and the patient's characteristics and the course of the pregnancy were analyzed. Logistic regression was used to determine the association between hematological parameters and the risk of GDM. Data were analyzed using SPSS, version 25.0 (SPSS, Chicago, IL).

Results: The final analysis included 310 pregnant women. The GDM group showed a higher pre-pregnancy BMI compared to the healthy controls (p < .01). There was no difference in NMR, PLR, and NLR between the groups (p = .63, .54, and .39, respectively). GDM was only positively associated with MLR (p = .02). After adjusting for potential confounding risk factors including maternal age, parity, and BMI, the multivariate regression analysis showed a higher level of MLR, with a cutoff point of 0.312, was independently associated with the risk of GDM (OR = 2.15, 95%CI 1.51-4.31, p = .03). However, ROC analysis showed that the AUC value of MLR was poor (0.670).

Conclusions: We found that MLR, an inflammatory combined index derived from whole blood counts, may potentially serve as a predictor of GDM in the early second trimester.