All nine months of pregnancy, the mother and the baby have a relationship due to the umbilical cord extending from the abdominal wall of the fetus (this place, which has a kind of scar after birth, is called the navel) and attached to the placenta. The umbilical cord is a cord in the form of a twisted spiral containing one vein and two umbilical arteries. Arterial blood with oxygen and nutrients from the placenta to the fetus enters the umbilical arteries. Blood enriched in carbon dioxide and metabolic products returns through the vein from the fetus to the placenta. A possible entanglement of the umbilical cord poses a threat to the life of the fetus due to oxygen starvation (intrauterine hypoxia). After cutting the umbilical cord at birth, he begins to live separately from his mother. Early cutting of the umbilical cord (in the first few seconds after giving birth) leads to a loss of arterial blood and a deficiency of iron and hemoglobin in the blood of the newborn.
It protects the vessels of the umbilical cord (from any harmful effects and mechanical damage), a special gelatinous material surrounding them, consisting of mucopolysaccharides, and called jelly warton. The umbilical cord allows not only the exchange of arterial and venous blood between the mother’s body and the fetus, but also movements in the amniotic fluid, during which umbilical cord entanglement can occur. Developing with the baby, the umbilical cord at the time of its birth usually corresponds to the growth of the newborn (an average of 55 cm) and has a diameter of one and a half to two centimeters.
Many anomalies of the umbilical cord are known; they cannot always be determined using prenatal ultrasound. Many of them are not obvious before delivery. Only in the case of monochorionic twins (identical twins with a common placenta), not separated by a septum, as well as placenta previa (with the risk of its detachment), you can get an early warning. Such an anomaly as umbilical cord entanglement forms risk factors that are characterized by various complications and suggest certain behaviors to prevent related diseases and mortality.
For unknown reasons, the umbilical cord length in 5% of cases may be less than 35 cm, and in 5% of cases longer than 80 cm. Short umbilical cords restrict and disrupt intrauterine movements of the fetus, and also create a risk of premature placental abruption. Too long umbilical cord contributes to entanglement of the fetus, that is, entwining of the umbilical cord may occur due to the formation of true nodes. Evaluation of the length of the umbilical cord prenatally (that is, before delivery) is not possible. In addition to true nodes during pregnancy, false nodes can also form on the umbilical cord. True nodules account for approximately 1% of pregnancies with a high proportion of cases of monochorionic twins. False nodes (kinks in the vessels of the umbilical cord) are more common, but not dangerous to the fetus.
The true umbilical cord node occurs due to fetal movements and most likely develops in early pregnancy, when a relatively large amount of amniotic fluid (amniotic fluid) is observed , so the fetal movement is more intense. The risk of true nodule formation directly depends on the age of the mother, the length of the umbilical cord and the amount of amniotic fluid. Frequent stress and increased levels of adrenaline in the blood contribute to increased fetal mobility.
A possible entanglement of the umbilical cord is diagnosed by fetal hypoxia during cardiotocographic studies. Then an ultrasound examination is carried out, as a result of which the presence of loops formed by the umbilical cord in the neck is examined. They also conduct color Doppler studies and study the movement of blood through the vessels. If fetal hypoxia is suspected, these studies are repeated several times during the pregnancy of the woman, since as a result of fetal movement, the nodes can not only become confused, but also become untangled. Umbilical cord entangling during childbirth causes bradycardia of the fetus. Permanent monitoring of the fetal heart rate allows reducing the risk, stimulation is also used to accelerate the delivery, and in case of urgent need, an operation is performed to urgently remove the fetus - cesarean section.