12 obstetric weeks of pregnancy is an important milestone in the development of the baby: the first trimester ends, the placenta is practically formed, the main risk of developing severe pathologies and spontaneous abortion is already behind. We learn what the fruit can "boast" in 12 weeks and how its development takes place on this date.
Anatomy of the fetus 12 weeks
At 12 weeks, the human embryo, or rather the fetus, has finally taken shape and resembles a tiny little man. All organs are in their places, but most of them are not yet active, only the largest and most vital ones work. Thus, the four-chamber heart beats at a frequency of about 150 beats per minute, the liver begins to produce the bile necessary for digesting fats, the intestine makes peristaltic cuts, and the kidneys produce urine.
The fetal brain of 12 weeks is similar to the miniature brain of an adult: all its departments are formed, and the big hemispheres are covered with convolutions. The pituitary body, located at the lower surface of the brain, begins to produce hormones.
The baby is still disproportionate: the head is noticeably larger than the trunk. At 11-12 weeks the fetus is still very thin and does not look like a newborn baby. Time to store fat will come later, and now muscles are forming and growing, the formation of bone tissue begins, in the gums appear the rudiments of permanent teeth, and on the fingers of the hands and feet - tiny nails. Now he needs calcium and protein more than ever, so a future mother should enrich her diet with products containing these substances.
By the end of the 12th week the formation of the reproductive system of the child is coming to an end. Now with the help of ultrasound you can determine whether a boy is born or a girl. In the blood of the baby, in addition to red blood cells (red blood cells), there are white blood cells (white blood cells), which means that one's own immunity appears. True, before birth and several months after it, the mother's immune bodies will protect the crumbs.
Fetal development 12 weeks
By the end of the first trimester the baby weighs almost 14 g, and its growth from the crown to the tailbone is 6-7 cm. The brain is growing rapidly, the nervous and muscular systems develop. The kid can grimace, open and close his mouth, squint, wiggle his fingers and toes, squeeze and unclench his fists and somersault in the uterus. For the future mother, acrobatic exercises are still fragile: the wiggling of the fetus at 12 weeks is still weak and inconspicuous. There are some unconditioned reflexes: by touching the uterus, the fruit pushes away from it, sucks its finger or fist, turns away from the bright light.
During this period the child can already distinguish the taste, swallowing the amniotic fluid. If the mother ate something bitter or sour, the little one shows how tasteless the taste is to him: wrinkles his face, puts out the tongue, trying to swallow as little as possible amniotic fluid.
In addition, the baby begins to do respiratory movements. Of course, these are not yet full breaths and exhalations: the vocal cavity is closed and the amniotic fluid does not enter the lungs. However, the baby's chest periodically heaves and falls - this training of the respiratory muscles will last until the end of pregnancy.
What can you see on ultrasound in 12 weeks?
As is known, from the 12th week all women in the situation are being given the first screening ultrasound in pregnancy . This is not done in order to determine the sex of the child (external sex signs are still not very noticeable). The main task of the study is to exclude the presence of severe developmental malformations and fetal pathologies.
Particular attention is given to:
- the size of the fetus at 12 weeks (normally the baby weighs 14-19 g, its height is 7-8 cm, the size of the head is 21 mm, and the diameter of the chest is 24 mm);
- thickness of the collar space (it should not exceed 3 mm, otherwise the risk of chromosomal abnormalities is possible);
- development of the placenta (it is important to exclude premature aging of the placenta and other pathologies);
- the location of the fetus at week 12 (there may be a low placental location, but, as a rule, with time, the placenta "migrates" towards the bottom of the uterus).