Stages of fetal formation in weeks

Stages of fetal formation in weeks

How pregnancy occurs

The real pregnancy starts at the woman two weeks after the first day of her last menstrual period. The mature egg emerges from its cone in one of the ovaries. It is transferred to the fallopian tube. This stage is called ovulation; Specifically, the beginning of pregnancy, it begins when one sperm succeeds among the millions of sperm produced by male fertilizing the female egg when intercourse.

Vaccination takes place by combining both male and female parenterals together to form a fertilized egg, starting with a phase of successive splits and important changes that differentiate the cellular mass and helping them to cultivate within the uterine wall. This cellular mass then develops into a series of divisions that ultimately result in the formation of the body And then exposed to the small body to the stages of growth in the womb of his mother; to acquire during the nine-month pregnancy nature reflected through the normal life aspects of the fetus completed after the emergence of the uterus, In fact, women do not feel pregnant during the simple period of fertilization and fetal culture; they may not feel it before four weeks of pregnancy or subsequent menstrual periods; as a symptom of pregnancy .

Stages of pregnancy

The total number of weeks of pregnancy is usually forty weeks, starting from the first day of the last cycle of the woman. The first and second weeks are not a real pregnancy because they do not include the fetus being carried in the womb of the woman; they are limited to the descent of the egg, fertilization of the egg , And then migrated to the uterus; to implant themselves in his belly, and yet enter these two weeks in calculating the stages of pregnancy months and weeks.

The stages of pregnancy can be divided into three sections:

  • The first stage: Starting from the first week, extending to the end of the thirteenth week.
  • The second phase: Continue from the 14th week until the end of the 27th week.
  • third level: The census starts from the beginning of the 28th week until the birth of the child in any given week.

Stages of fetal formation in weeks

The first stage of pregnancy

  • First and second weeks: These two weeks are the beginning of the pregnancy and its first stage, in which the ovulation occurs in the female on the fourteenth day, and then fertilizes the egg, to become a fertile mature fertilized egg, and this egg is transferred to the uterus to implant in the lining of the uterus announcing the start of pregnancy.
  • the third week: The fertilized egg enters a series of equal divisions starting from the second week, forming a cellular mass of sixteen cells called the Morula. The thymus is transferred to the uterus to grow in the two weeks of the second and third periods. (Blastocyst), which is characterized by two groups: one will be the members of the different embryo, called the internal cellular mass, while the other called the feeder.
  • fourth week: The differentiation of the fetus begins into two layers: internal, external, and the placenta develops by the effect of hormones that prevent the extinction of endometrial cells, and increases the thickness and the abundance of blood vessels in them.
  • The fifth week: The heart starts to pulse, the blood flow is organized, and the fetal growth is rapid compared to the fourth week. The upper and lower limbs appear, and some organs begin to grow, such as the liver, kidneys, and intestines.
  • the sixth week: This week, some of the details of the fetus appear simple: the opening of the nostrils, the ears, and two black spots begin to appear in the eyes, and the limbs begin to separate from the embryo’s body.
  • Seventh week: This week, the heart and pulse of the fetus are visible. The pulse can be measured by ultrasound, the blood circulation begins to function regularly, and the internal organs grow with the development of its physiological functions, such as kidneys, liver, and brain.
  • The eighth week: The limbs appear more clearly, the fingers are ready to appear, the eyelids appear, the bones begin to form, and the child’s body does not appear to be consistent at this time; the size of his head is greater than his body.
  • Week Nine: The fingers and toes are clearer this week, but they are still incomplete, the shape of the attachment that is capable of doing the job, and the growth of arms and feet.
  • Week 10: This week is characterized by the emergence of some new details, such as: nails, and clarity of the spine, and the completion of the growth of internal organs, such as: the heart, kidneys, liver, brain, with the performance of physiological functions fully, and highlights the shape of the forehead and its level in the head of the fetus.
  • Week 11: The bones of the fetus begin to become rigid, and the tooth buds are formed under the gums. The skin of the embryo is still transparent. Blood vessels appear easily through it. This week, the growth of the fingers and their separation from each other is complete.
  • Week 12: The fetus breathes by amniotic fluid, its brain growth rate slows down compared to the previous weeks, and as the kidneys complete, the fetus dumps its waste into amniotic fluid.
  • Week 13: This week, ear growth is completed, the growth of tooth buds and vocal tendons continue, and the child has the muscular capacity of swallowing.

Second stage of pregnancy

  • Week Fourteen: The growth of the liver and spleen is completed; the liver excretes the bile, and the spleen is the task of producing red blood cells. The fetus acquires flexibility and activity, increasing its movement and kicking, but it has not yet reached the threshold of the mother’s sensation.
  • Week 15: In this period, it is possible to identify the sex of the baby via ultrasound technology. As for size, the leg growth is longer than the arms. The joints work well. The limbs are given freedom of movement in proportion to the muscles. The formation of the alveoli in the fetus begins Stage.
  • Week 16: The movements of the arms and legs are active, with strong strokes that give the mother a feeling and feeling of the nature and position of the movements. On the organizational level, the thyroid gland is able to secrete hormones for metabolism.
  • Week 17: In this week, the hair appears on the baby’s head, eyebrows and eyelashes. Biologically, the metabolic process begins as a result of the thyroid gland’s secretions and hormones. Most organs work in the fetus’s body, such as urinary and circulatory systems. Light, and responds to sensation.
  • Week 18: The ears are placed in place on either side of the head, and the eyes take their best place. The female genitals are made up of the vagina, the fallopian tube in the uterus.
  • Week 19: The nerve cells are responsible for smell, taste, hearing, sight and touch, and the size of the neurons increases. Neural connections become more intense. More complex among them.
  • Week Twenty: The fetus is released for the first time in this period. Fecal matter consists of dead skin residues and digestive secretions accumulated in the fetus’s intestines, which makes the stool innocuous in the body of the fetus or the body of the mother.
  • Week Twenty-first: The feeling of the fetus begins this week; as a result of the development of its sense of touch; it feels the wall of the uterus when it touches him, and hears the sounds around him, and responds to the external sound effects, and hair cover the whole body;
  • Twenty-second and twenty-third weeks: The fetus grows exponentially, with the end of the twenty-third week reaching about 30 cm, while its weight increases to about 600 g.
  • Twenty-fourth and twenty-fifth weeks: The fingers of the embryo show fine fingernails, with different hands that are sensed and explored, with long-path nerve connections.
  • Twenty-sixth and twenty-seventh weeks: The two eyes gradually open up, the nerve network attached to the ears is completed, and the baby swallows sips of water through its primitive respiratory attempts, reaching a length of 36.5 cm at the end of the period, and weighing about 900 g.

Third stage of pregnancy

  • Weeks from 28th to the end of the thirty-second: This layer protects the skin of the embryo from the surrounding medium within the mother’s womb. This layer soon disappears with the previously infected skin layer. At the end of this period, the uterus prepares the body for the birth stage, reverses the direction of the fetal head Down little by little.
  • Weeks thirty-third to thirty-sixth: There is nothing special at this stage except the processing of the birth position, the continuous rotation with the fetus to the pelvic area, the brain building is completed, and the bones are hardened, and the testicles move from the abdominal cavity of the male fetus towards the scrotum.
  • Thirty-seventh and thirty-eighth weeks: The embryo layer completely disappears and consists of a fatty layer that regulates the fetus’s temperature and prepares for its release into the new world. During this period, all embryos are complete except for the lungs. Their growth and differentiation are complete after birth. The weight of the fetus varies between 3-3.2 kg. It is different where males are born at a slightly larger size than females, as the nails of the fetus grow and grow, and the stool is formed inside the stomach.
  • Forty-ninth week: The embryo takes a specific position at the bottom of the pelvis; its head is down, the vestibular layer disappears before birth, and the fetus swallows amounts of the fluid that turns into the fetus’s stomach into droppings and prepares the uterus for entry into labor.