Fetal Development During Pregnancy

Pregnancy is a very special condition of a woman. The expectant mother needs not only to register in a timely manner and be monitored by a specialist, but also to devote a lot of time to self-education. It does not matter at all what week of pregnancy you are now. The guide we offer will be useful in any case and will help you better understand your own condition. With such a help, you will be able to find out what changes occur with the fetus from the first week, how the fetal development takes place, what happens to his weight, the formation of body parts, growth. We have tried to give a detailed description of the pregnancy course by week.

Embryo is the early stage of the development of a living organism, at which it is still in the egg or in the uterus. The term “embryo”, when referring to a person, is applied to an organism developing in the womb until the end of the 8th week from the moment of conception, from the 9th week it is called a fetus.

Our pregnancy guide will become your assistant and will help you find out exactly what happens to the body in the first weeks, and what changes you expect in the future. We described the peculiarities of a woman’s well-being during this important period and the specifics of embryo development.

The stages of fetus development

1-4 weeks

The egg grows and matures in the ovary before conception. Ovulation is the movement of a mature egg from the ovary into the fallopian tube. Ovulation occurs in the middle of the cycle. When a mature egg and a sperm are combined, fertilization occurs. From this moment the development of the future baby begins.

At week 4, the size of the embryo is only 2-4 mm. As a rule, a woman does not feel anything and often does not even guess about the onset of pregnancy.

5-8 weeks

The embryo grows, almost a million new cells are formed in it every minute. By the end of the 7th week, it already reaches one centimeter in length. By the end of the 8th week, the future baby will grow to 1.5-2 cm. At this time, primitive neural pathways begin to form in his brain. During an ultrasound examination with CT (coccygeal-parietal size) of more than 4 centimeters, the specialist will be able to determine the heartbeat.

9-12 weeks

The second trimester begins at the 14th week. The baby has the first hairs during this period. By the 16th week, the child’s muscular and nervous system are sufficiently developed, he grows up to 16 cm, the eyes become sensitive to light stimuli, the first movements of the facial muscles appear.

17-20 weeks

In the womb, the baby grows and develops intensively. By the end of the 20th week, the baby’s skin becomes less transparent than it was before. This is due to the beginning of subcutaneous fat accumulation. The motor brain neurons are sufficiently developed, which allows the baby to make a variety of movements, including even putting his thumb in his mouth.

The child’s body grows, so his head ceases to look so bulky.

21-24 weeks

The beginning of the sensory receptors’ formation falls on the 21st week. The child develops a tongue and taste buds, the brain is able to process tactile sensations. At the end of the 22nd week, the child’s weight will be approximately 500 grams, its length will be about 25 cm. Next comes the development of the nervous system and brain.

25-28 weeks

At this time, the period of the most active growth comes to an end. From the 20th to the 30th week, the baby’s weight doubles, by the end of the period, the weight is already within 1-1.5 kg. The baby’s eyelids are not tightly closed until the 28th week, which contributes to the retina development.

During these weeks, the child begins to distinguish tastes, to hear sounds. It is possible to note his numerous movements in response to various sounds and touches. The nervous system and brain are in the stage of rapid growth and development.

29-32 weeks

Mom’s third trimester is coming. The baby’s organs mature, it grows and accumulates fat deposits. By the 32nd week, the baby’s length will be approximately 40 cm, its weight will increase to 2 kg.

The baby begins to train the respiratory muscles, moves a lot and even hiccups sometimes, i.e. makes hiccup movements. He practices breathing.

33-36 weeks

The 36th week will end for the unborn baby with a weight of 2.4-2.8 kg, his height will be approximately 48 cm. Further, the weight of the child will grow by 200 g weekly. Thanks to the layer of fat cells, the facial features will become rounded, the facial muscles are already adapted for sucking. Often during an ultrasound examination during this period, it is clearly visible how the baby is trying to put a fiest in his mouth or just sucks a finger.

37-40 weeks

On average, by the 40th week, the baby’s height is 51-53 cm, weight – 3-4 kg. The baby is already fully moving in the womb and uses legs and arms. Kids have developed grasping skills, they can blink and swallow, stretch their legs and turn their heads. Moms can clearly distinguish between periods of sleep and wakefulness. The sucking reflex becomes as pronounced as possible. The baby is ready to be born and begin the next stage of life.