The birth of a child is a very complex and responsible process. Every expectant mother wants to know how the embryo develops by week. After all, this action is securely hidden from human eyes, but carefully studied by scientists.
So, the development of the embryo by week
The first few hours after conception. The sperm enters the egg and fertilization takes place. Up to eight weeks, the resulting fetus is called an "embryo".
1-2 weeks. Active cell division occurs. The embryo moves through the fallopian tube, enters the uterus and by the end of the second week is fixed on its mucous membrane. The sex of the unborn child is already determined at this stage, and it depends on the set of chromosomes that contained the sperm that fertilized the egg.
3-4 weeks. Despite the fact that the fetus is very tiny, his heart is already beginning to pulsate. Gradually, the nervous system, bone and muscle, is born. As a rule, during this period, a woman begins to guess about her pregnancy, since there is no menstruation.
5th week. The length of the embryo is about 6-9 millimeters. He is already developing a headache andspinal cord, the central nervous system is formed. The heart separates, arms, legs, a head with holes for the eyes, mouth and nose appear.
6th week. The placenta is formed. During this period, it serves the baby as a liver, lungs, kidneys, stomach.
7th week. The length of the embryo already reaches 12 millimeters, and the weight is 1 gram. The fetus has its own vestibular apparatus and begins to move, however, due to its tiny size, the movement is not felt by the woman.
8th week. The development of the child by weeks of pregnancy proceeds dynamically and systematically. The embryo has already formed a body. You can distinguish the face, nose, ears. The nervous system continues to improve and the skeleton grows. The first rudiments of the genital organs appear.
9th week. The whole body of the baby already has sensitivity. He can touch himself, the umbilical cord.
10-13 weeks. This stage is one of the most important in the process of intrauterine development, since the nervous system and most organs are actively developing. The fetus begins to make the first swallowing movements. As a result of the active development of the skeleton, its size is rapidly increasing, which entails the growth of the pregnant tummy. During this period, the baby already hears, the vocal cords are formed.
14-16 weeks. The kidneys and bladder begin to function, the fetus takes its first breaths and exhalations, opens its eyes. Significantly increased physical activity.
17-20 weeks. Photos of the embryo by week during this period show that all parts of the body are already clearly visible. The baby opens his mouth, blinks. Due to the fact that its dimensions already exceed 14 centimeters, the expectant mother begins to feel light tremors.
21-25 weeks. The weight of the fetus rapidly increases, the first fat deposits appear. The lungs of the baby are quite developed, and in the case of his premature birth after 23 weeks, there is a great chance of survival with intensive care. The baby's heartbeat begins to be heard if you put your ear to the pregnant woman's stomach.
26-30 weeks. The development of the embryo by week during this period is very active. So, a sucking reflex is formed, the first hairs on the head and eyelashes may appear, nails grow.
31-35 weeks. The baby's skin becomes thicker. During wakefulness, he opens his eyes, in a dream he closes. The brain is actively developing, the number of convolutions is increasing. The lungs are fully developed and the grasping reflex is developing.
36-40 weeks. The period of waiting and preparation for childbirth. Starting from this moment, you can expect the first contractions - harbingers. The abdomen drops, the cervix shortens. The body is preparing for childbirth. At this stage, the development of the embryo by weeks is completed. The baby calms down, pushes less, because due to its significant size it becomes cramped. From 38 weeks, the baby is considered full-term.
