Determination of the diameters of fetal umbilical artery and umbilical vein in 12 - 28 gestational weeks in screening thalassemia with ultrasound

Abstract

Objective To study the value of the diameters of fetal umbilical artery and umbilical vein in early prenatal screening program for thalassemia by ultrasound.Methods A total of 120 cases of singleton pregnant with thalassemia at 12- 28 gestational weeks were detected by ultrasound,328 cases of normal singleton pregnant at 12 - 28 gestational weeks were selected as controls.The diameters of fetal umbilical artery and umbilical vein were tested and compared between the two groups.The diagnostic values were evaluated by ROC curve.Results At 12 - 15+6 gestational weeks,the diameters of umbilical artery and umbilical vein of thalassemia group were larger than those of control group(P ＜0.05).At 16 - 19+6 gestational weeks, the diameter of umbilical vein of thalassemia group was larger than that of control group,the differences were significant (P ＜0.05).The cutoff threshold of the diameter of fetal umbilical artery was 1.80 mm,the diameter of fetal umbilical vein was 2.95 mm at 12 - 15+6 gestational weeks,the diameter of fetal umbilical vein was 3.80 mm at 16- 19+6 gestational weeks,which were obtained by ROC analysis.The sensitivity of this cutoff threshold to identify thalassemia were 83.3％, 83.3％, 47.8％,respectively, while the specificity were 90.5 ％, 95.2 ％, 85.4％, respectively.Conclusions The diameters of fetal umbilical artery and umbilical vein detected by ultrasound have great value on early prenatal screening of thalassemia, these indexes can be used as an important factors in early prenatal screening of thalassemia. Key words: Ultrasonography ; Thalassemia; Umbilical artery; Umbilical veins