External validation of a risk-scoring model for predicting adverse perinatal outcomes in pregnancies with fetal growth restriction

Aim

This study aimed to validate the Prince of Songkla University (PSU) risk-scoring model for predicting adverse perinatal outcomes in pregnancies with an antenatal diagnosis of fetal growth restriction (FGR) in an independent cohort.

Methods

A retrospective study was conducted on 121 non-anomalous singleton pregnancies affected by FGR between July 2022 and April 2024. The predictive performance of the PSU risk-scoring model, which combines maternal factors and simple ultrasound measurements to predict adverse perinatal outcomes in FGR, was evaluated by applying the original model to this independent cohort. Model variables included a history of hypertensive disorders of pregnancy (HDP) (1 point), chronic hypertension (3 points), HDP (2 points), maternal weight gain <8 kg (1 point), early-onset FGR (1 point), estimated fetal weight < 5th percentile (2 points), amniotic fluid index <5 cm (3 points), and abnormal umbilical artery Doppler (2 points). Predictive performance was evaluated using area under the receiver operating characteristic curve (AUC). Sensitivity and specificity were calculated at different cut-off values.

Results

Median (interquartile range) gestational age at FGR diagnosis was 29 (22–39) weeks. Adverse perinatal outcomes occurred in 35 cases (28.9%). A cut-off score of 2 provided the highest sensitivity (85.7%) with a specificity of 51.2% for predicting adverse perinatal outcomes, with an AUC of 0.809 (95% confidence interval 0.714–0.905).

Conclusions

This study confirms the predictive performance of the PSU risk-scoring model for adverse perinatal outcomes in FGR pregnancies, highlighting its potential to identify at-risk patients for referral, particularly in low-resource settings.