The first trimester of pregnancy
After conception the fertilized egg moves through the fallopian tube and embeds itself in the uterine endometrium at this time is constantly going on cell division and development of the layers of the embryo which further develops the organs, tissues, and amniotic shell. 2-3 week development of baby-to-be has an oval shape with a size of 0.2-0.4 mm.
To the 5th week of pregnancy ultrasound of the uterus is determined by an amniotic egg with a size of about 18 mm. the Size of the embryo does not exceed 1.5 mm, the remaining space fills icteric pouch.
In the first trimester of pregnancy, size of unborn child increasing pretty quickly. Each week, the embryo grows by almost half. 6 weeks the embryo and to understand the rudiments of basic bodies, clearly the chord indicated the brain. On the 7th week already visible handles, clearly marked to the eye, but saved the tail. From the 8th week of fetal development are highlighted in the legs.
By the end of the first trimester at 12 weeks the embryo has the shape of a small child, his kopcik-parietal size of about 5 cm during this period, the fetus is clearly visible eyes, mouth, nose, fingers and toes have nails. Already distinctive sexual characteristics of the child appear the makings of a sucking reflex, i.e., the embryo begins to swallow amniotic fluid.
Free space in the gestational SAC allows the baby to freely float, it performs infrequent movement of arms and legs.
The second trimester of pregnancy
During the second trimester of fetal improve all laid organs and systems. More active starts functioning nervous system, so the fetus responds to external stimuli – responds to all sounds, quietens down to classic tunes, distinguish between the voices of parents, squinting in contact with bright lights on the belly of the mother.
To the 18-20th week pregnant woman begins to feel movement of the baby, therefore, can discern that he does not like. If the expectant mother lay on its side, and the fetus uncomfortable in this position, he will aggressively "kicking". When mom is nervous, the baby is restless.
5-6 month of pregnancy the baby's skin takes on a pink color, the face and body are covered with a thin layer of grease. This period can be clearly seen facial features, and appear eyebrows.
By the end of the second trimester the baby starts sucking their fingers, actively swallows amniotic fluid. When spazmirovannah diaphragm the fetus can hiccup. At this stage of fetal development begin to function of the kidneys and intestines.
The third trimester of pregnancy
In the last trimester the baby is gaining weight and growing. At 24 weeks, the fetal weight is about 700 g, kopcik-parietal size - 30 cm Towards the end of pregnancy the weight can exceed 3 kg. the Growth of the newborn is about 50 cm At this time, the fetus develops subcutaneous tissue, it is already possible to consider the first folds. Many children are actively growing hair, and they are born with thin curlicues.
In the third trimester the baby is asleep and awake, on my own time, he was able to open and close the eyes.
In a gestational SAC at this period the fetus becomes crowded. The child is not actively moving, and often sticks out a hip or elbow, sometimes can be felt through the mother's abdomen, little heels. On 8-9 month fetus usually descends head down and preparing for birth.