To explore the value of ultrasonic markers of first trimester in prediction of trisomy 21, trisomy 18 and trisomy 13 syndrome.

Totally 1564 pregnant women were collected from Beijing Obstetrics and Gynecology Hospital, Capital Medical University from September 2014 to May 2016. All the cases underwent the ultrasound screening during 11 to 13^{+ 6} weeks and the chromosome results were Trisomy 21, Trisomy 18, Trisomy 13 or normal. The effects of using different kinds of ultrasonic markers combination to predict chromosomal abnormalities were evaluated by the area under the receiver operating characteristic curve (AUC), sensitivity, specificity and Youden index.

The results of multivariate Logistic regression model suggested that maternal age (OR=1.05, 95%CI: 1.01-1.10), nasal bone hypoplasia (OR=14.54, 95%CI: 2.28-92.75), nuchal translucency (NT) thickening (OR=12.46, 95%CI: 8.27-18.78), the crown-rump length (GRL) decrease (OR=12.79, 95%CI: 1.45-113.14), fetal edema (OR=9.69, 95%CI: 3.55-26.48) were the risk factors of common trisomy syndromes. Using these factors to establish Model A, the the AUC, sensitivity, specificity and Youden index of were 0.770, 0.630, 0.904 and 0.534. While the results of using NT thickening and age to establish the multiple Logistic regression model (Model B) were 0.756, 0.618, 0.907 and 0.525. NT thickening and age were used as single variable, and the other 8 ultrasonic markers were combined into a new variable (other abnormality), and the results of establishing a multiple Logistic regression model (Model C) were 0.775, 0.642, 0.902 and 0.543.

NT thickening in early pregnancy ultrasonic markers is of great significance in predicting the common trisomy syndromes in fetuses, and the combination of other ultrasonic indicators can optimize the prediction effect to some extent.