Will the umbilical cord still be around the neck after the baby enters the pelvis? It is most important to do a good prenatal check-up

Many pregnant women have experienced the phenomenon of the umbilical cord wrapped around the fetus' neck. If it is serious, it may threaten the baby's life. Therefore, expectant mothers must have regular prenatal checkups. If the umbilical cord is found around the fetus' neck, fetal heart rate monitoring should be done and an appropriate delivery method should be chosen.

1. Will the umbilical cord still be around the neck after the fetus enters the pelvis?

Umbilical cord around the neck is likely to occur when the umbilical cord is too long, the fetus is too small, the amniotic fluid is too much, and the fetal movement is too frequent. When the umbilical cord is wrapped around the fetus and then the fetus passes through the umbilical cord loop to form a true knot, it is very likely to lead to a lack of blood supply to the fetus, causing ischemia and hypoxia. Umbilical cord prolapse is prone to occur when the fetal presenting part cannot be connected. It is mostly caused by abnormal fetal position, high floating fetal head, or cephalopelvic disproportion, small fetus, excessive amniotic fluid, and too long umbilical cord. Causes of umbilical cord around the neck: The umbilical cord around the neck is related to its length and fetal movement. For example, frequent spontaneous rotation of the fetus or external version can lead to its occurrence. For full-term infants with the umbilical cord wrapped around the neck for one week, the umbilical cord length should be 18 to 20 cm, and the longer the cord is, the longer it is wrapped around the neck. The longer the umbilical cord is, the shorter the umbilical cord can also wrap around the neck.

Since umbilical cord around the neck is very common, it does not necessarily mean a high-risk pregnancy. However, we need to be aware that the umbilical cord around the neck may have adverse effects on the perinatal fetus. Patients with fetal heart rate decelerations before and during delivery may have significantly increased perinatal morbidity and mortality during delivery. Strengthening fetal monitoring before and during delivery and choosing the correct delivery method can reduce the morbidity and mortality of neonates with umbilical cord around the neck.

2. Examination of umbilical cord around the neck

Ultrasound examination is the only way to diagnose umbilical cord around the neck, but the accuracy of ultrasound diagnosis is not completely reliable. Even experienced sonographers may misdiagnose or miss the nuchal cord. Doppler ultrasound can provide hemodynamic information of umbilical vessels, including blood flow velocity, resistance index, pulsatility index and other parameters, providing a strong basis for determining whether a fetus with umbilical cord around the neck is experiencing intrauterine distress.

1. Scanning technique

During routine inspections of suspected umbilical cord entanglement, the probe is scanned along the longitudinal axis of the fetus at that location, and the probe is rotated to both sides. With that location as the axis, the probe is slid as far as possible to perform an arc scan. The probe is placed horizontally at that location to perform compensation scans on the upper and lower sides.

2. Ultrasound manifestations

There is a depression on the fetal surface in this area. One week is "U" shaped, two weeks are "W" shaped, and more than two weeks can be arranged in parallel or overlapped and staggered, and the skin depressions have different appearances. The umbilical cord extends posteriorly to the opposite side of this part. When determining that the umbilical cord is entangled, if the umbilical cord is floating and at a distance from the surface of that part of the fetus, and there are tortuous and floating umbilical cord echoes in other parts, it means that the entanglement is loose. If the umbilical cord is tightly attached to the winding part, the umbilical cord echo is difficult to detect in the amniotic fluid, or the umbilical cord is stretched and pulled, it should be considered that the winding is too tight or the umbilical cord is too short.