At the same time, outwardly they have nothing in common with those anatomical structures that are observed in the middle of pregnancy. So far, these are only small bulges from individual groups of cells.
What does the future child look like at the 3rd week of pregnancy after conception?
In general, it looks like a small ear concha, around which a small amount of liquid is located. This amniotic fluid, with an increase in the period, the volume of which grows.
The size of the embryo now does not exceed 1.5-2 mm. It can be examined exclusively with the help of an ultrasound machine with a high resolution.
What happens at such a short time?
During 3 weeks, the embryo has respiratory cracks, which look very primitive. However, they themselves are the germs of the future respiratory system of the fetus.
At the same time, a separate group of cells separates, from which a nervous system of crumbs begins to form after a short time. Practically at the same time, rudiments of the future spinal cord and brain are formed.
At the head end, the eye fossa begins to form, the baby's future eyes. They are still so small that they can be viewed at high magnification. However, the color, the cut is already defined, because this occurs even at the time of the fusion of the sex cells.
Begin to appear the rudiments of organs, which in the future form the endocrine system of the child. This pancreas and thyroid gland. At 3 weeks from conception, the first blood cells appear in the embryo. They are the so-called precursors of blood cells, erythrocytes. Already by the 19th day, the heart tube begins to cut itself. The heart is formed from it directly through perfection.
What changes does the future mother mark?
This time is exactly the moment when most women find out about their interesting situation. The level of hCG at the 3rd week of pregnancy from conception reaches those values that are sufficient for diagnosis. In most cases, even an ordinary rapid test gives a positive result. Normally, the concentration of hCG at this time is approximately 1100-31500 mIU / ml. It is worth noting that this parameter alone can not carry a diagnostic value, and is regarded only as an indicator. Therefore, a discrepancy in the concentration of a hormone normally requires a second study, while confirming the result - an additional examination.