To explore the predictive value of detection of fetal ultrasound soft indexes in fetal chromosomal abnormalities.

A total of 123 fetuses who underwent fetal chromosome detection at Wuxi Maternal and Child Health Hospital Affiliated to Nanjing Medical University from January 2017 to December 2021 were selected in study. According to the results of fetal chromosome detection, they were divided into abnormal chromosome group (n=23) and normal chromosome group (n=100) by retrospective analysis method. All fetuses in two groups received color Doppler ultrasound to detect thickness of nuchal translucency (NT) at 11 to 13 weeks of gestation, and the other fetal ultrasound soft indexes such as umbilical venous catheter a-wave reverse, left ventricular focal hyperecho, intestinal echo enhancement, choroidal cyst, short humerus/femur, lateral ventricle widening, and separation of renal pelvis were detected at 18 to 27 weeks of gestation by color Doppler ultrasound. At 18-20 weeks of gestation, amniotic cavity puncture under the guidance of ultrasonic puncture probe was conducted for fetal chromosome detection. The incidence of fetal ultrasound soft indexes abnormalities between two groups was compared by chi-square test or continuity correction chi-square test or Fisher′s exact probability test. Multivariate unconditional logistic regression analysis was conducted to analyze influencing factors of fetal chromosomal abnormalities. Receiver operating characteristic (ROC) curve was used to evaluate the value of fetal ultrasound soft indexes for predicting fetal chromosomal abnormalities. The procedure followed in this study conformed to the regulations of the Ethics Committee of Wuxi Maternal and Child Health Hospital Affiliated to Nanjing Medical University, and was approved by this committee (Approval No. 2022-06-0714-28). All mothers of fetuses signed informed consents for clinical study. There were no statistical differences between two groups in general clinical data, such as gestational age at ultrasound detection in the first and second trimester of pregnancy and mother′s age, and so on (P>0.05).

①There were 17 cases (73.9%) of fetal ultrasound soft indexes abnormalities in abnormal chromosome group and 12 cases (12.0%) in normal chromosome group. The incidence of fetal intestinal echo enhancement and NT thickening in abnormal chromosome group both was 26.1% (6/23), which was significantly higher than 1.0% (1/100) and 4.0% (4/100) in normal chromosome group, and both the differences were statistically significant (χ²=7.78, 9.43; P=0.005, 0.002). ②Multivariate unconditional logistic regression analysis results showed that fetal ultrasound found intestinal echo enhancement and NT thickening both were independent risk factors of chromosomal abnormalities in fetus (OR=5.392, 5.557; 95%CI: 1.843-15.776, 1.899-16.257; P=0.005, 0.009). ③Area under the curve (AUC) of fetal intestinal echo enhancement combined with NT thickening in fetal ultrasound for predicting fetal chromosomal anomalies was 0.776 (95%CI: 0.654-0.898, P<0.001).

Fetal ultrasound soft indexes including fetal intestinal echo enhancement and NT thickening both are closely related to fetal chromosomal abnormalities. The combination detection of these two fetal ultrasound soft indexes in predicting fetal chromosomal abnormalities is of medium value.