摘要
To the Editor:The umbilical cord is the vital link between the fetus and the placenta.The proper spiral state of the umbilical cord plays a key role in maintaining its function.The umbilical coiling index(UCI)is the number of spiral cycles per 1 cm of length and is normally 0.17,with UCI>0.30 considered hyper-coiling.^([1])Previous studies have identified hyper-coiling umbilical cord significantly associated with adverse pregnancy outcomes.^([2])However,many other studies have failed to find a strong correlation between abnormal coiling and adverse outcomes.^([3])Whether there are other abnormal ultrasound indicators in the hyper-coiling cord(HC)that can give early warning of adverse pregnancy still needs to be further explored.
