Pregnancy is an amazing dynamic physiological process that occurs in the female body.
The duration of this process is measured in different ways. At the household level it is accepted to measure it in months. Pregnancy lasts 9 calendar months. In medicine, a more accurate measurement system has been adopted. The entire period of intrauterine development of the fetus is divided into stages (stages) by weeks. The weekly measurement system allows the most accurate determination of important periods of fetal development.
Physiological pregnancy lasts 40 weeks ± 2 weeks.
According to the calendar of intrauterine development of the fetus, you can monitor the process in dynamics. It shows in the form of a table the process of development of the fetal organs for weeks and looks like this in the following way.
Let's take a more detailed look at the norms of fetal development for weeks.
Fetal development chart by week
- 1-4 weeks. In the first weeks of development the fetus is called the embryo. The fertilized egg quickly divides and reaches the uterus on day 3-4. Then the embryo attaches to its walls of the uterus and continues to exist as an embryo. The development of the fetus (still an embryo) in the first weeks of pregnancy begins with the formation of the neural tube, which is nothing more than the backbone of the future spinal cord and brain. The third week is the laying of the respiratory, digestive, circulatory and other body systems. The intestines, lungs and liver are laid in the fourth week. The spine is formed.
- 5 week . The development of the fetal system and organs continues. The liver begins to work.
- 6 week. Begins convergence of the eyes, visible rudiments of ears and spout. Limbs begin to be divided into elbows, shins, shoulders, hips, palms, feet. The brain starts to control the work of the muscles and heart.
- 7 week. The bone system is developing. Jaws are defined. Eyes are protected for centuries.
- 8 week. The brain departments are being formed. The fetus can already react to some inconvenience by wincing or wrinkling. On the face begin to stand out the first features, on the legs and handles appear fingers.
- 9 week. All parts of the heart are already formed. The fruit can move the handles and legs, open the mouth and rotate the head.
- 10 week. The formation of the reproductive organs of the fetus continues. The eyes are fully developed.
- 11 week. Due to the development of receptors, the sensitivity of the skin increases.
- 12 week. The fetus can already make various movements: twirl your head, wiggle fingers and toes, open and close your mouth, suck your finger.
- 13 week. The first trimeter of pregnancy came to an end. All the main organs are laid. All parts of the digestive system begin to function.
- 14-15 weeks. The excretory system begins to work. Functional transformations of the brain occur.
- 16 week. A smile appears on the child's face. First hair, eyelashes, eyebrows grow.
- 17-18 weeks. The pituitary, pancreatic and thyroid glands begin functioning. Improves the coordination of the child's movements.
- 19 week. A vestibular apparatus is formed. There is a facial expression.
- 20-21 weeks. Wrinkles on the fetus are smoothed. Completing the formation of nail plates and auricles.
- 22 week. Lungs formed and filled with a special liquid.
- 23 week. The nervous system performs its functions: the child can react to external stimuli.
- 24-25 weeks. The development of the liver, intestines, and stomach has been completed.
- 26 week. The fetus is able to express its taste and olfactory preferences.
- 27-28 weeks . The limbs of the baby are rounded. The child can use touch, hearing, smell.
- 29-30 weeks. The immune system begins its activity.
- 31 week. The child takes the position of the "embryo": folded handles and pre-tight legs.
- 32 week. There is a turn of the baby in a position downward head.
- 33-34 weeks. The kid is studying his body and the world around him at the level of sensory sensations. The maturation of the lungs is coming to an end.
- 35-36 weeks. The liver accumulates iron reserves in intensive work. The skin is smoothed.
- 37-38 weeks. The brain and head continue to grow. Accumulates brown fat, which will protect the baby in the first months of life from hypothermia.
- 39-40 weeks. Mobility of the baby decreases. He is preparing for birth.
- 41-42 weeks. Those who have not yet been born before this time, continue to gain weight and are waiting for birth.
