During pregnancy, new organs appear in the female body, which are necessary for the full intrauterine development of the fetus. One of them is the umbilical cord. This article will tell you about this unique organ, vital for the growth and development of a baby in the womb.
What it is?
Doctors call the umbilical cord the umbilical cord, which connects the small embryo, and then the fetus with the placenta. Through this special "bridge" the child's body is connected with the mother. This connection occurs almost in the very first months of pregnancy and lasts until the onset of childbirth.
Interestingly, the umbilical cord is found not only in humans. This organ is also found in all vertebrates that develop embryonic membranes during pregnancy. However, the structure of the umbilical cord in humans is different. It is much more complex than that of other mammals.
The umbilical cord has two ends. One of them attaches to the abdominal wall of the fetus, and the other to the placental tissue. In the place where the umbilical cord is attached to the baby's tummy, in the future there will be a familiar "mark" - the navel. It will appear after the baby is born and the doctor will cut the umbilical cord with a special tool.
Histologically, the umbilical cord is largely composed of connective tissue. It also contains elements from the previous embryonic membranes, the amniotic membrane, and other components.
Appearance
A characteristic feature of the umbilical cord is the way it looks. The umbilical cord is a rather long "cord" that can form loops. The longer the umbilical cord, the more loops it can form.
The umbilical cord is usually gray-blue in color. The presence of a blue tint is due to the fact that there are veins inside the umbilical cord. The umbilical cord is a truly unique organ as it only appears during pregnancy. After the baby is born, the umbilical cord is cut. This means the birth of a new person.
The outer surface of the umbilical cord is fairly smooth and even. The mucous membranes are quite shiny in appearance. The umbilical cord has good elasticity. This can be felt after the baby is born by cutting the umbilical cord. The density of the umbilical cord is somewhat reminiscent of soft rubber.
Structure
Despite the fact that the umbilical cord in its appearance resembles a simple cord, its anatomical "structure" is rather complex. So, blood vessels pass inside the umbilical cord, as well as other anatomical elements. Each of them has its own structural features, and also performs certain functions.
Arteries
Through the umbilical arteries, fetal blood, which contains a lot of carbon dioxide, flows to the placental tissue. Also in this blood are metabolites that were formed in the child's body.
The umbilical arteries are branches of the mother's internal iliac arteries. Scientists have determined that in each period of pregnancy a certain amount of blood flows through the umbilical cord. So, by the 20th week of pregnancy, about 35 ml of blood per minute flows through the umbilical arteries. How much blood flows through the arteries, the same amount of blood flows through the veins. This biological principle underlies the functioning of the child's body.
Gradually, the amount of blood flowing to the placenta increases. So, by the final weeks of pregnancy, this figure is already 240 ml per minute. The larger the baby becomes, the more blood flows through the umbilical blood vessel system.
The umbilical arteries function only during pregnancy. After the child is born, they “close” and turn into special strands. Experts also call them medial umbilical folds (ligamenta medialis umbilicalis). These cicatricial cords run under the parietal leaf of the peritoneum on the anterior abdominal wall, lateral to the bladder. The medial umbilical folds extend all the way to the navel.
Veins
Initially, the umbilical veins are paired. Over time, obliteration (closure) of the right umbilical vein occurs. Blood flows through them from the placental tissue, enriched with oxygen and nutrients. In this case, most of the blood enters the inferior vena cava system through a special venous (Arancian) duct. A smaller part enters the portal bloodstream. This happens through the anastomosis between the left branch of the portal vein and the umbilical vein itself. This blood is essential for the blood supply to the liver tissue.
Urachus
This particular thin duct connects the bladder and placenta. By the time the baby is born, the urachus is completely closed. It turns into a cicatricial cord called the ligamentum medianum umbilicale. It is a long strip that runs along the midline of the abdominal cavity.
In practice, there are cases when the urachus does not close completely. In such a situation, the risk of developing pathology is quite high. A urachus cyst is a pathological condition in which an incomplete closure of this embryonic duct occurs.
Yolk duct
This anatomical element is an elongated cord that connects the intestine of the embryo to the yolk sac. The yolk sac contains nutrients important for intrauterine development. They are still stocked with an egg before conception. The main nutritional component is lecithin.
This anatomical element is retained only in early pregnancy. Subsequently, the vitelline duct gradually overgrows. Certain pathologies can also be associated with it. So, if its closure does not occur by a certain date, then this can lead to the development of a pathological condition - the formation of a Meckel diverticulum.
Vartonov jelly
This anatomical element is very important. It performs many different functions that are necessary for the full intrauterine development of the fetus. The basis of Wharton's jelly is connective tissue. The appearance of this anatomical element is peculiar. It has a gelatinous or jelly-like consistency, which in its chemical composition is represented mainly by mucopolysaccharides.
The main function of Wharton's jelly is to protect the blood vessels, which are inside the umbilical cord, from various mechanical influences. Also, gelatinous fluid protects the umbilical arteries and veins from various kinks and compression.
It should be noted that the warton jelly contains its own blood vessels. They are quite sensitive to the important pregnancy hormone oxytocin. This sensitivity is especially evident during childbirth. When a baby is born, the level of oxytocin in the female body decreases, which leads to the fact that the blood vessels in the warton jelly begin to close. This reaction leads to the fact that the umbilical cord begins to atrophy rather quickly. The blood flow through it is maintained only for a certain time.
Length is normal
This indicator can be different. The length of the umbilical cord is an individual value. Even in one woman, the length of the umbilical cord can change during different pregnancies. Scientists have determined that the normal length of the umbilical cord is approximately 40-70 cm.
This length of the umbilical cord is necessary so that the baby can freely perform active movements. During the intrauterine development of a child, the amplitude and number of movements performed by him significantly increase.
Active physical activity and an excessively long or short umbilical cord can become the reasons for the development of dangerous pathologies.
A variety of reasons can lead to lengthening. Doctors believe that the length of the umbilical cord may even depend on a genetic predisposition. Statistics indicate that the length of the umbilical cord during repeated pregnancies may be greater than during the first.
There are many reasons that can lead to lengthening of the umbilical cord during pregnancy. In each case, they are different. With excessive lengthening of the umbilical cord, certain pathologies of the course of pregnancy may develop. In this case, doctors closely monitor the development of pregnancy.
Functions
The main function of the umbilical cord is to provide the fetus with all nutrients and oxygen to feed it. The baby during his intrauterine life in the mother's womb cannot eat on his own. He "feeds" on proteins, fats and carbohydrates, which he receives through the blood from his mother. The fetus feeds in this way throughout its intrauterine life.
The umbilical cord is also a kind of "bridge" between mother and baby. During the intrauterine life of the fetus, not only a biological, but also a mental connection is formed between him and his mother. Many scientific studies have shown that, at a certain period of its development, the baby is able to feel the mother's experiences and even respond to changes in her mood.
How is it attached to the placenta?
The attachment of the umbilical cord to the placenta is a very important clinical criterion. The nature of the baby's intrauterine development even depends on how the umbilical cord attaches to the placental tissue.
The most physiological option is to attach the umbilical cord to the middle of the placenta. Doctors also call this option central. In this situation, the risk of developing any complications during pregnancy is quite low.
However, in obstetric practice, there are also cases when the umbilical cord is attached to the placenta "incorrectly". Attachment can occur in the edge area or even to shells. In this case, dangerous complications can develop during pregnancy that can affect the well-being of the child in the mother's womb.
Various pathologies
The umbilical cord is a very important organ. Its physiological structure ensures the full growth and development of the baby, which "lives" in the mother's tummy. If any defects appear in the structure of the umbilical cord, then this can contribute to the development of dangerous pathologies.
Entanglement
A rather unfavorable pathology that can develop during pregnancy is the umbilical cord entanglement of the child's neck. Usually, this situation develops if the length of the umbilical cord exceeds 70 cm. Too long an umbilical cord begins to fold into loops that entangle the child.
The loops of the umbilical cord can wrap not only the neck, but also the abdomen, as well as the limbs of the fetus. The prognosis of the course of pregnancy and the upcoming birth depends on how the umbilical cord loops are located on the child's body.
So, if the loop of the umbilical cord is in the cervical groove of the baby and squeezes it strongly, then this can lead to the development of asphyxia during natural childbirth. If there are several loops, then this situation can be extremely dangerous. As a rule, with a strong multiple entanglement, doctors try to prevent natural childbirth, and plan in advance for a cesarean section.
Umbilical cord entanglement is not always an absolute indication for a surgical method of obstetrics. Caesarean section with such a pathology is carried out if the risk of developing various injuries and injuries during natural independent childbirth is quite high.
Nodes
Another possible pathology that can lead to a disruption in the course of normal pregnancy is the appearance of nodes on the umbilical cord. Experts identify several types of such formations. So, nodes can be true and false.
True nodes are usually formed in the first half of pregnancy. The child at this time is still quite small and very mobile. Vigorous physical activity of the baby can lead to the fact that the umbilical cord begins to "get tangled" and nodules appear on it.
The consequences of this pathology can be different. The presence of a large number of nodes on the umbilical cord can lead to a disruption in the blood supply of the child's body with oxygen and nutrients, which contributes to the development of intrauterine hypoxia. In this case, the child's internal organs cannot fully function, which contributes to the formation of pathologies.
Also, true nodes can become a certain "obstacle" in natural childbirth. During the passage of the baby through the birth canal, such nodules on the umbilical cord can be severely tightened, which will lead to a threat to the child's life.
In such a situation, urgent surgical intervention by doctors is required. It so happens that every minute of delay in the provision of medical care is crucial.
In obstetric practice, there are also false nodes. In this case, the diameter of the umbilical cord increases. The prognosis of the course of pregnancy in the presence of false nodules on the umbilical cord is usually favorable.
Dropping out
The biomechanism of childbirth has strict sequential stages. Due to the fact that the child gradually moves through the birth canal, his birth is not accompanied by the development of any injuries or dangerous injuries. However, if the biomechanics of childbirth is disturbed, then in such a situation, very dangerous conditions can develop during childbirth.
One of them is the loss of the umbilical cord loops. In this case, the umbilical cord penetrates into the cervix and even into the vagina immediately with the discharge of amniotic fluid. In such a situation, when the fetus moves through the birth canal, dangerous conditions can arise. The child can simply pinch the umbilical cord, which will lead to a sharp decrease in the level of oxygen in his blood. Oxygen deficiency in this case will lead to the development of hypoxia, which ultimately can even lead to impaired cardiac activity in the fetus.
Obstetricians-gynecologists note that the risk of umbilical cord loops falling out is quite high in case of premature birth, complicated by presentation. A pregnant woman may face this situation while not in the hospital. Outpouring of amniotic fluid with loss of umbilical cord loops can occur anywhere - for example, on the street, at home, in a park or in the country. In this situation, an ambulance team should be urgently called.
A pregnant woman who has had an early prolapse of the umbilical cord loops should be urgently hospitalized in a hospital.
Cysts
It usually becomes possible to determine a cystic formation in the umbilical cord only, as a rule, when a child is born. Unfortunately, even modern ultrasound machines do not allow doctors to find out about the presence of this pathology during pregnancy. Diagnosis of umbilical cord cysts is quite difficult.
According to statistics, cysts in the umbilical cord are most often formed in Wharton's jelly. The number of cystic lesions may vary. So, only one or a few cysts may be present.
Note that not always in the presence of a cyst in the umbilical cord, a pregnant woman has any complications of the course of pregnancy. Quite often, with a small and single cyst, the expectant mother and her baby do not experience any adverse symptoms.
If there are a lot of cysts and they pinch the blood vessels that are in the umbilical cord, then in such a situation the child develops uncomfortable symptoms. So, the baby's heart rate or even his physical activity may change.
Experts identify several clinical variants of cysts. So, they can be true and false. A pseudocystic formation located in Wharton's jelly does not have a capsule. Scientists have not yet precisely established the cause that leads to their appearance.
A true cyst is often formed from elements of the vitelline duct. It usually has a capsule. The size of a true cyst is different - from a few millimeters to 1.5 cm.
Differential diagnosis of false and true cysts is often extremely difficult. This can be done only after the baby is born, when the umbilical cord is sent for histological examination.
Vascular thrombosis
The detection of this pathology during pregnancy has become possible thanks to modern ultrasound techniques. During an ultrasound scan, the doctor can determine thrombosis (blockage) of the umbilical vessels. The cause of this occlusion is a blood clot that blocks the lumen of the umbilical cord blood vessel.
Some scientists believe that diabetes mellitus, which the expectant mother suffers during pregnancy, can lead to the development of this pathology. Also, the risk of developing thrombosis of the umbilical cord vessels is high in women who suffer from blood clotting pathologies.
Thrombosis, according to statistics, most often develops in the umbilical vein. The prognosis for the development of pregnancy with such a pathology is usually unfavorable. The development of further pregnancy largely depends on how large the thrombus is and how severe the functional disorders are.
Umbilical cord blood test
In certain cases, cordocentesis is required during pregnancy. This diagnostic procedure involves drawing blood from the blood vessels in the umbilical cord.
Cordocentesis is an invasive procedure. This means that the risk of developing possible complications is quite high. One of them is fetal infection. Given the danger of such severe complications, cordocentesis is performed only for strict medical reasons.
After childbirth
After the birth of a child, doctors must assess the condition of the umbilical cord. In order to "separate" the baby from his mother, the umbilical cord must be cut.
Previously, only doctors did it. Now the father of the baby can also cut the umbilical cord if he is in the delivery room when the baby is born. This unique opportunity is now being used by more and more parents. Usually, in the process of cutting the umbilical cord, the baby's father feels real pride, joy and tenderness.
How is it cut?
Many women think that only scissors are used to cut the umbilical cord. In practice, this is not entirely true. Obstetricians-gynecologists can use a variety of tools to cut the umbilical cord after the baby is born. Before cutting the umbilical cord, the doctor puts special clamps or clamps on it. This is necessary in order to "restrict" blood flow through the blood vessels.
When cutting the umbilical cord, it is important to remember that it still contains arteries and veins. The blood that is in the umbilical vein is used to determine the Rh factor and blood type in a newborn baby.
The stump, which is located next to the umbilical ring in a born child, gradually begins to dry out, and then completely departs. However, in caring for a newborn, it is important to remember that it is quite easy to "bring" a dangerous infection into this area. To prevent such dangerous infectious complications, doctors make up a set of recommendations for the expectant mother and must explain to her how to monitor the umbilical cord stump.
Note that for some time after birth, the baby's umbilical cord pulsates. This is totally normal. At this time, you should not rush to cut the umbilical cord. Too rapid intervention can lead to the fact that oxygen-rich blood from the umbilical cord cannot fully enter the child's body. In this case, the baby's hemoglobin level may be reduced.
American scientists believe that the umbilical cord should be cut with a certain delay of a couple of minutes. Their research shows that in this case, the level of hemoglobin in the baby is slightly higher. Also, according to American experts, the baby with such a "delayed" cutting of the umbilical cord will gain weight better, and the risk of developing various pathologies that are possible in the first six months of a child's life will be significantly lower.
Note that not all obstetricians-gynecologists share the opinion of their American colleagues. Quite a lot of doctors practicing in European countries cut the umbilical cord within the first minute from the moment a baby is born. They argue that cutting the umbilical cord “early” reduces the risk of infection during childbirth.
For the structure and purpose of the umbilical cord, see the next video.
