How Common Are Umbilical Cord Knots?
Umbilical knotting is one of the abnormalities of the umbilical cord. There are two types of umbilical cord knots: false umbilical knot and true umbilical knot. Umbilical cord pseudoknot refers to the umbilical cord is longer than the umbilical cord, the blood vessel curls like a knot, or the umbilical vein is longer than the umbilical artery to form a tortuous knot, which is generally not a major clinical hazard, and rarely bleeds due to ruptured blood vessels. Umbilical cord true knots are relatively rare, caused by the umbilical cord forming a loop in the uterine cavity, and the fetal movement through the loop, the incidence rate is 0.5% to 3%. The true knot of the umbilical cord may affect fetal blood circulation and cause fetal death in the womb.
Basic Information
- English name
- knot of umbilical cord
- Visiting department
- Obstetrics and Gynecology
- Common causes
- The umbilical cord is too long
- Common symptoms
- Fetal hypoplasia or intrauterine death, etc.
Causes of umbilical knot
- Umbilical true knot: Because the umbilical cord is too long, the umbilical cord forms a loop in the uterine cavity, and the fetus moves through the loop.
- Umbilical cord pseudoknots: Because the umbilical vessels are longer than the umbilical cord, the vessels curl like knots, or because the umbilical veins are longer than the umbilical artery, they form tortuous knots.
Clinical manifestations of umbilical cord knots
- After the true knot of the umbilical cord is formed, there are no symptoms if the knot is not tightened, such as fetal hypoplasia or fetal death caused by obstruction of fetal blood circulation after tightening.
- Umbilical cord pseudoknots are generally asymptomatic. Rarely bleeds due to ruptured blood vessels and generally does not affect the fetus.
Umbilical cord knot check
- Because the fetus survives in amniotic fluid, the surface contrast of the ultrasound image is strong, and almost all fetuses can make three-dimensional surface images, which can accurately observe the fetal face, limbs, chest and abdomen, and spine. Therefore, ultrasound examination can be used to observe and judge the umbilical cord's direction in the uterine cavity and its relationship with the fetus.
Umbilical cord knot diagnosis
- The true knot of the umbilical cord is difficult to find before delivery, and most are diagnosed after delivery. Three-dimensional ultrasound imaging, that is, 3D ultrasound, can sometimes help to determine the direction of the umbilical cord in the uterine cavity and its relationship with the fetus, and it has a certain rate of accurate diagnosis of umbilical knots.
Umbilical Knot Treatment
- If the fetal blood circulation is not affected, no treatment is required.
- If umbilical cord blood pressure is found to cause intrauterine distress and the fetus is viable, the fetus should be delivered as soon as possible.
Umbilical cord knot prevention
- Umbilical knots are difficult to prevent. B-ultrasound is simple, fast, and economical, and it is a preliminary inspection method for umbilical cord abnormalities. On the ultrasound screen, the umbilical cord image can be clearly displayed, and the neck of the fetus caused by the umbilical cord entanglement can be seen. If it is the umbilical cord around the neck, the number of turns of the umbilical cord around the neck can also be preliminarily determined.
- Normal fetal movement is about 50 to 200 times per day, and the range fluctuates greatly. Each pregnant woman has its own rules. If the umbilical cord around the neck has caused fetal distress, the fetal movement will change significantly. Early fetal hypoxia is manifested by excessive fetal movement or frequent fetal movement, and late fetal manifestation is reduced fetal movement. Pregnant women with an umbilical cord around their neck should pay special attention to their fetal movement patterns and changes, and seek medical attention if abnormalities are found.