Objective To investigate the roles of triglyceride glucose-body mass index (TyG-BMI) and retinol-binding protein (RBP) in the occurrence of fetal distress due to exposure to stressful life events in late pregnancy.

Methods From December 2021 to June 2023, a cohort of 482 women in late pregnancy was recruited from the General Hospital of Ningxia Medical University. A self-designed questionnaire was employed to collect data of general maternal health. The Pregnancy Life Events Scale was adopted to quantify stressful life events, and blood samples were collected for metabolic biomarker measurement. Participants were followed through delivery, and the obstetric outcomes were recorded. R 4.3.0 was used for descriptive statistics, LASSO regression analysis, binary logistic regression analysis, and Spearman correlation analysis. A chain-mediated effect model was constructed in SPSS AU to evaluate the associations of exposure to stressful life events in late pregnancy, TyG-BMI, and RBP with fetal distress. Sensitivity analyses were performed to assess the robustness of the findings.

Results The incidence of exposure to stressful life events among women in late pregnancy was 31.54%, and that of fetal distress was 13.07%. Stressful life events, RBP, TyG-BMI, and anxiety were significant predictors of fetal distress. Logistic regression results showed that pregnant women exposed to stressful life events had a 2.10-fold higher risk of fetal distress compared with those without exposure (OR = 2.10, 95%CI: 1.06–4.16). For every one-unit increase in TyG-BMI, the risk of fetal distress increased by 1% (OR = 1.01, 95%CI: 1.01–1.02). For every 1 mg/L increase in RBP, the risk of fetal distress decreased by 5% (OR = 0.95, 95%CI: 0.92–0.98), indicating that RBP may have a protective effect against fetal distress. Spearman correlation analysis revealed a positive correlation between TyG-BMI and RBP (r = 0.177, P < 0.001). Chain-mediate effect analysis showed that TyG-BMI had a complete mediating effect on the impact of stressful life events on fetal distress through RBP, with a total indirect effect value of −0.001.

Conclusions Exposure to stressful life events in late pregnancy has a complete mediating effect on fetal distress through TyG-BMI and RBP, and RBP may play a protective role between insulin resistance in late pregnancy and fetal distress.