The 13th week in fetal development is quite significant, it is at this time that a relationship is established in the "mother-child" system.
Let's consider how the baby develops on this period of pregnancy.
Placenta
At this time, the placenta finishes its formation. Now she is fully responsible for the development of the fetus, producing the right amount of hormones of estrogen and progesterone. The thickness of the placenta is approximately 16 mm. It is a hard barrier to various harmful substances, but at the same time it passes through the carbohydrates, fats and proteins necessary for the fetus.
Fetal size at week 13 of pregnancy
The fruit at 13 weeks has a weight of about 15 - 25 g and a size of 7 - 8 cm. The heart of such a tiny creature a day already pumps 23 liters of blood. By the end of 13-14 weeks the fruit will have a length of 10-12 cm, weight 20-30 g, and a head diameter of about 3 cm.
Development of fetal organs and systems at the 13th to 14th week of pregnancy
Intensively begins the development of the brain. Reflexes appear: the sponge of the baby is twisted, the hands are compressed into fists, it can start, grimace, pull fingers into the mouth. For some time the fruit spends quite actively, but most of the time it sleeps.
The delicate and tender skin of the baby continues to develop, there is still no subcutaneous fatty tissue, so its skin is wrinkled and red with small blood vessels appearing on the surface.
The formation of the bone system is actively proceeding. At 13 weeks, the fetus already has a sufficiently developed thyroid gland, due to which the calcium deposits in the bones. The bones of the limbs are gradually becoming longer, the process of ossification of the skull and bones of the spine begins, the first ribs appear, the beginnings of twenty milk teeth .
The fetus at the 13th week of pregnancy also has a well-formed respiratory system. The baby is breathing. If the fetus begins to suffer from a lack of oxygen, then some of the amniotic fluid enters its lungs.
At this time the prostate gland begins to develop in boys. Girls are actively breeding germ cells. The sexual organs continue to differentiate more and more: the genital tubercle becomes longer and gradually turns either into the penis or into the clitoris, bending downward. Thus, the external genitalia become developed enough to distinguish the girl from the boy.
In the intestines of the baby there are villi, which play an important role in the process of digesting and promoting food. Blood cells begin to form in the liver, bone marrow, and spleen of the fetus. The development of the first portions of insulin begins with the pancreas. The baby's voice machine begins to be created.
The sense of smell develops - the baby catches the smell and taste of the food that his mother uses. Not all of the mother's menu can be to his liking, and he especially likes certain dishes. Scientists have found that if a woman after a birth dramatically changes the diet, it can lead to certain problems in breastfeeding, because the baby keeps in mind the smells he smells in-fetus.
As for the appearance of crumbs, it eventually acquires more and more expressive features. The head of the fetus no longer presses against the chest, the bridge of the nose, the superciliary arches, and the chin are clearly defined. The ears are in their normal position. Eyes approach each other, but they are still covered with fused eyelids.
Most of the work on laying the basic organs and systems of the body has already been done, it is time for the formation of the emotional sphere. At this time, the kid always listens and begins to react to signs that come from the outside world (cold, warm, dark, light, sounds, touches), mastering new skills.