Early Detection of Fetal Growth Restriction: Contribution of the HALP Score and First-Trimester Maternal BMI

Aim: To evaluate the predictive value of the first-trimester Hemoglobin, Albumin, Lymphocyte, and Platelet (HALP) score for fetal growth restriction (FGR), and to examine whether combining the HALP score with maternal body mass index (BMI) enhances risk prediction.Materials and Methods: We retrospectively analyzed prospectively collected data from pregnant women followed at a tertiary center between January 2023 and June 2025. A total of 176 singleton pregnancies were included, consisting of 88 women diagnosed with FGR and 88 gestational age–matched controls. First-trimester hematological parameters were used to calculate the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and HALP score. Diagnostic performance was assessed using receiver operating characteristic (ROC) analysis, and subgroup analyses were performed according to maternal BMI.Results: The HALP score was significantly lower in the FGR group than in controls (p<0.001). A higher HALP score was independently associated with a lower likelihood of FGR (OR: 0.40, 95% CI: 0.25–0.62; p<0.001). ROC analysis demonstrated that the HALP score had the highest diagnostic accuracy, with an AUC of 0.845 (95% CI: 0.783–0.895). At a cutoff value of ≤3.31, the sensitivity and specificity were 80.68% and 78.41%, respectively. In exploratory subgroup analyses among women with low HALP scores, overweight women (BMI 25.0–29.9 kg/m²) had a lower likelihood of FGR than women with a BMI <25 kg/m². However, no formal HALP × BMI interaction analysis was performed.Conclusions: The first-trimester HALP score is a valuable predictor of FGR. Exploratory analyses suggest that the combined evaluation of HALP and maternal BMI may improve risk stratification, although formal interaction analyses are required to confirm this observation. Prospective multicenter studies are warranted to validate these findings.