International Journal of Clinical Obstetrics and Gynaecology

Background: Fetal growth restriction (FGR) is a major cause of stillbirth, prematurity, and long-term developmental issues. Early prediction using biomarkers from the first trimester may enable timely preventive actions like aspirin use. Combining uterine artery Doppler indices with maternal serum biochemical markers may significantly improve prediction, but data from low- and middle-income settings is still limited.

Objective: To create and validate a predictive model for FGR using first-trimester uterine artery Doppler indices and maternal serum markers.

Methods: A prospective cohort study was conducted with singleton pregnancies between 11+0 and 13+6 weeks. Measurements included uterine artery pulsatility index (UtA-PI), presence of early diastolic notching, maternal serum pregnancy-associated plasma protein-A (PAPP-A), free ?-human chorionic gonadotropin (?-hCG), and placental growth factor (PlGF). Clinical factors included maternal age, BMI, parity, and smoking status. FGR was defined as a birth weight below the 10th percentile with Doppler evidence of placental insufficiency. A multivariable logistic regression model was built and validated internally using bootstrapping. External validation was done with an independent dataset. Model performance was evaluated based on discrimination (AUC), calibration, and decision curve analysis.

Results: In the development group of 720 women, 86 (11.9%) experienced FGR. Key predictors included high UtA-PI, bilateral notching, low PAPP-A, low PlGF, and high maternal BMI. The final model achieved an AUC of 0.86 (95% CI: 0.81-0.89). In the external validation cohort (N=350), AUC was 0.83 (95% CI: 0.78-0.87). The calibration slope was 0.94. Decision curves indicated clinical value at risk thresholds between 5% and 20%.

Conclusion: First-trimester uterine artery Doppler indices combined with maternal serum markers provide high predictive accuracy for FGR. The validated model may help identify risk early and direct preventive measures.