Objective: This study aims to investigate the formation factors that affect the angle of nuchal cord and explore the types of nuchal cord that exist and the process of standardized ultrasound diagnosis of nuchal cord.
Methods: Ultrasonography was performed on 707 fetuses with nuchal cord, to observe the direction of the coil, determine the type of coil, and analyze the correlation between the fetal position, placental location, and the direction of the coil with the angle of the umbilical cord.
Results: Among the 707 fetuses, those with 1 loop accounted for 89.67%, fetuses with 2 loops accounted for 6.08%, fetuses with 3 loops accounted for 0.28%, and fetuses with partial draping of the umbilical cord accounted for 3.96%. Nuchal cord mostly occurred in fetuses where the placenta was attached to the anterior wall of the uterus, and the α-shaped and C-shaped types were in the majority. The C-shaped type accounted for 43.14%, the α-shaped type for 40.88%, the O-shaped type for 12.02%, and the L-shaped type for 3.96%.
Conclusion: The direction of the coil of the umbilical cord can be determined by blood flow vector observation. The fetal position, placental location, and the direction of the coil are the three factors affecting the coiling angle of the umbilical cord. Ultrasonic classification of nuchal cord can provide detailed information, which can be used by physicians when performing surgery on the fetus. The advances in the diagnosis procedure allow the diagnosis of nuchal cord to be carried out in an orderly manner, making it more accurate and standardized.
Keywords: nuchal cord, coiling direction, ultrasonic classification, diagnostic process, standardization