Abstract: This paper explored the clinical value of umbilical venous catheter (UVC) color Doppler ultrasound blood flow spectrum parameters in the first trimester combined with four-dimensional color Doppler ultrasound in the second trimester in the diagnosis of fetal congenital cardiac developmental malformations. A total of 62 fetuses with congenital cardiac developmental malformations were selected as the observation group, and 180 fetuses with normal heart development during the same period were selected as the control group. Both groups received UVC color Doppler ultrasound examination at 11 to 13 weeks of gestation, and four-dimensional color Doppler ultrasound examination at 17 to 27 weeks of gestation. The results showed that the measured values of fetal UVC color Doppler ultrasound blood flow spectrum parameters atrial systolic peak velocity (A), ventricular diastolic peak velocity (D), ventricular systolic velocity (S) and A wave maximum velocity (Tamax) in the observation group were lower than those in the control group (P<0.05). The measured values of fetal UVC color Doppler ultrasound blood flow spectrum parameters pulsatility index (PI), venous preload index (PLI) and venous peak velocity index (PVIV) in the observation group were higher than those in the control group (P<0.05). The AUC values of S, D, A, Tamax, PI, PLI and PVIV in the first trimester were 0.702, 0.849, 0.647, 0.768, 0.826, 0.757 and 0.676, respectively. The overall coincidence rate of four-dimensional color Doppler ultrasound in the diagnosis of fetal cardiac malformation in the second trimester was 93.55%. The sensitivity and specificity of four-dimensional color Doppler ultrasound in the diagnosis of cardiac developmental malformations were 93.55% and 98.33%. The application of UVC color Doppler ultrasound blood flow spectrum parameters in the first trimester combined with the four-dimensional color ultrasound screening in the second trimester has a better effect on the detection of fetal congenital cardiac malformations and measures.

Key words: early pregnancy, umbilical vein catheter, color Doppler ultrasound, blood flow spectrum, four-dimensional color ultrasound, congenital heart disease