Many pregnant women are interested in questions about what functions the yolk sac performs, what it is, and when it occurs. After all, it is no secret to anyone that this is an extremely important element that ensures the normal development of the embryo.
Yolk sac - what is it?
During an ultrasound examination in the early stages of pregnancy, the doctor draws attention to the size and development of this particular structure. The yolk sac is a special extra-embryonic organ that is formed in the initial stages of pregnancy and performs extremely important functions in the first months. It is located in the umbilical cord and is first closely associated with the fetal gut. This formation is formed from mesoderm cells and has the shape of a ring with thin walls.
The main functions of the yolk sac
In fact, this education is extremely important. At the initial stages of development, the embryo and yolk sac are closely related. Firstly, this structure is a source of nutrients. Secondly, the yolk sac is actively involved in the breathing process.
On approximately the eighteenth day of pregnancy, the first red blood cells begin to form in the yolk sac. This structure also provides the formation of the first capillaries, from which the fetal circulatory system will develop in the future.
On the 28th day, the first germ cells form in the walls of the bag, which subsequently become the main for the development of the gonads and the reproductive system of the child. In addition, the yolk sac during the first six weeks performs the functions of the liver: it is in its tissues that all dangerous substances and toxins are retained.
As you can see, this formation is extremely important for the normal development of the fetus. If the yolk sac does not function normally, then this threatens spontaneous abortion.
Where does the yolk sac go?
Every expectant mother knows that during pregnancy, the vital activity of the fetus directly depends on the functioning and condition of the placenta. But where does the yolk sac go? In the first three months, the embryo and placenta have time to fully form. At this stage, the formation of the placental type of blood circulation is completed, and the yolk sac is no longer needed. Its tissues are gradually reduced. Until the end of pregnancy, this formation remains in the form of a small cyst located near the umbilical cord.
Is yolk sac enlargement dangerous?
Since this structure is very important, it is only natural that it is examined during an ultrasound examination. You can see it starting from the sixth week from conception. At the 12th week of pregnancy, the yolk sac can no longer be examined using ultrasound.
At 5-10 weeks, the size of the bag should not exceed 5.5 millimeters. But in women who are pregnant for 8-12 weeks, the size of this formation, as a rule, is about 2 mm.
But sometimes the doctor notices that the yolk sac is enlarged. What does this mean and how dangerous? In fact, any deviation from the norm may indicate a threat to pregnancy. Naturally, this is not the final diagnosis, since other, additional studies are needed. For example, an increase in the yolk sac may be due to nutrition, certain medications, or severe stress. In any case, with similar ultrasound results, it is necessary to get poisoned by a gynecologist. Only a specialist knows why the yolk sac can be enlarged, what this means and whether special treatment is required.