Prediction of large‐for‐gestational age at 36 weeks’ gestation: two‐dimensional vsthree‐Dimensionalvs magnetic resonance imaging

Abstract

AbstractObjectiveTo compare the performance of two‐dimensional ultrasound (2D‐US) three‐dimensional ultrasound (3D‐US) and magnetic resonance imaging (MRI) at 36 weeks of gestation (WG) in the prediction of Large‐for‐Gestational‐Age (LGA) fetuses defined as birthweight > 95th percentile in a high‐ and low‐risk groups for macrosomia.MethodsThis was a prospective observational study conducted between January 2017 and February 2019. Women with singleton pregnancy at 36 WG underwent simultaneously 2D‐US, 3D‐US, and MRI. By plotting the weight estimations and the birthweight on the growth curve, a percentile was obtained, and it was used for comparison. The study population was divided into high‐ and low‐risk groups, according to at least one of the following risk factors: the presence of diabetes, suspicion of macrosomia during the third trimester (> 90th percentile at the ultrasound routine scan), obesity (body mass index, BMI, > 30 kg/m2), and excessive weight gain. The outcome was the measurement of the performance of each diagnostic modality in the prediction of birthweight > 95th percentile. Statistical analysis was performed by calculating the area under the receiver operating characteristic (ROC) curve (AUC), sensitivity, specificity, positive and negative predictive values for each modality.ResultsOut of 988 patients, 965 were eligible: 533 (55.23%) in the high‐risk group and 432 (44.77%) in the low‐risk group. In the low‐risk group, the AUCs were 0.982 for MRI, 0.964 for 2D‐US, and 0.962 for 3D‐US. No statistical significance was found among these three methods. In the high‐risk group, the AUCs were 0.959 for MRI, 0.909 for 2D‐US, and 0.894 for 3D‐US. A statistically significant difference between MRI and both 2D‐US (p = 0.002) and 3D‐US (p = 0.002) was found. MRI had the highest sensitivity (65.79%) compared with both 2D‐US (36.84%) and 3D‐US (21.05%) ultrasound (p = 0.002 and p < 0.001, respectively). The 3D‐US had the highest specificity (98.99%) compared to both methods (2D‐US: 96.77%, p = 0.005, and MRI: 96.97%, p = 0.004).ConclusionAt 36 WG, MRI performs better than 2D‐US and 3D‐US in predicting birthweight > 95th percentile at birth, especially in patients at high‐risk for macrosomia, while 2D‐US and 3D‐US are comparable. For low‐risk patients, the three modalities perform similarly.This article is protected by copyright. All rights reserved.