To explore the predictive factors of ultrasound for the adverse perinatal outcome of late-onset fetal growth restriction (FGR) and analyze their diagnostic efficacy.

A retrospective analysis was performed on the ultrasound images and clinical data of 149 patients with late-onset FGR who were admitted to the Third Affiliated Hospital of Zhengzhou University from December 2015 to May 2021. According to whether there were adverse perinatal outcomes, the patients were divided into an adverse perinatal outcome group (72 cases) and a control group (77 cases). General clinical data and middle cerebral artery pulsatility index (MCA-PI), umbilical artery pulsatility index (UA-PI), brain-placental rate (CPR), amniotic fluid-umbilical brain rate (AUCR), and estimated fetal weight (EFW) within one week before delivery were recorded. Two independent samples t-test, Mann-Whitney U test, and χ² test were used to compare the differences in the above indicators between the groups, and the ROC curve was plotted to analyze the predictive performance of each ultrasound parameter on the adverse perinatal outcome, and single factor and multivariate logistic regression analyses were used to identify the meaningful predictors.

Compared with the control group, the AUCR, EFW percentile, CPR, MCA-PI, and MVP of the adverse perinatal outcome group were significantly lower [30.63±10.33 vs 39.70±11.15, t=5.138, P＜0.001; 3.2 (2.1, 6.4) vs 5.7 (3.5, 8.9), Z=-4.618, P＜0.001; 1.18±0.28 vs 1.37±0.21, t=4.464, P＜0.001; 1.22±0.26 vs 1.34±0.23, t=3.129, P=0.002; 27.50 (22.00, 31.00) mm vs 29.00 (23.50, 34.50) mm, Z=-2.292, P=0.022], and UA-PI was significantly higher (1.05±0.20 vs 0.98±0.16, t=-2.504, P=0.013). Multivariate logistic regression analysis showed that AUCR, EFW percentile, and CPR were independent predictors of poor perinatal outcome of late-onset FGR (odds ratio=0.951, 0.753, and 0.154; P=0.024,＜0.001, and =0.044, respectively). ROC curve analysis showed that the cut-off value, sensitivity, and specificity of AUCR, EFW percentile, and CPR for predicting adverse perinatal outcome of late-onset FGR were 39.64, 53.2%, and 81.9%, 4.85, 66.2%, and 66.7%, and 1.19, 81.8%, and 51.4%, respectively. Multi-parameter model including AUCR, EFW percentiles, and CPR had improved diagnostic performance for poor perinatal outcomes, and made up for the imbalance between sensitivity and specificity of single parameter in predicting adverse perinatal outcomes of late-onset FGR. The area under the ROC curve of the model was 0.795, and the sensitivity and specificity were 76.6% and 70.8%, respectively.

Ultrasonography is of great value in predicting the adverse perinatal outcome of late-onset FGR. AUCR, EFW percentile, and CPR are independent predictors of adverse perinatal outcome of late-onset FGR, providing a basis for prenatal consultation and clinical management.