Pregnancy Calendar. Intrauterine Fetal Development

Pregnancy Calendar. Intrauterine development of the fetus.

Pregnancy is one of the most important and responsible events in a woman’s life. Within 280 days, or 10 obstetric months, the fertilized egg turns into a mature fetus, ready for life outside the uterus. In this article we will look at the stages of fetal development inside the uterus.

First month (4 weeks):

During the first month after conception, the zygote is fragmented and an embryo is formed. The embryo begins to form, the rudiments of the most important organs and embryonic membranes are formed. At the end of the first month the fruit is about 4 mm long.

Second month (8 weeks):

The length of the fetus reaches 3-3.5 cm, its body is formed, there are rudiments of limbs, the head is equal to the length of the body, the rudiments of eyes, nose, and mouth are visible on it. The formation of the genital organs begins.

Third month (12 weeks):

The length of the fetus is 8-9 cm, weight - 48 g. The head is large, the difference in the structure of the external genitalia is noticeable. The limbs move, fingers and toes are visible. The first points of ossification appear in the cartilaginous rudiment of the skeleton.

Fourth month (16 weeks):

The length of the fetus is 13.5 cm, weight - 120-180 g. The face is formed, the ossification of the skull occurs. The formation of the muscular system basically ends. Movements of the limbs become more active, but are not perceived by the mother. The sex of the fetus is clearly distinguishable.

Fifth month (20 weeks):

The length of the fruit reaches 18.5 cm, weight 280-300 g. The skin is red, covered with vellus hair. The sebaceous glands begin to secrete a fatty substance, which mixes with the scales of the epidermis and forms a cheese-like lubricant (vernix caseosa). Meconium forms in the intestines. The movements of the fetus are felt by the mother. When auscultating a pregnant woman's abdomen, you can listen to the fetal heartbeat.

Sixth month (24 weeks):

The length of the fetus is 25 cm, weight - 600-680 g. Movements become more energetic, the fetus can be born alive, make breathing movements, but soon dies.

Seventh month (28 weeks):

The fruit is 32 cm long, weighs 1000-1500 g. Subcutaneous fat is poorly developed, the skin is wrinkled, covered with a cheese-like lubricant, and there is vellus hair all over the body. Eighth month (32 weeks):

The length of the fetus is 40 cm, weight 1800-2200 g. Subcutaneous fat is developed, the skin becomes smooth, the parental organs reach full maturity. The fetus becomes less mobile due to lack of free space in the uterus.

Ninth month (36-40 weeks):

The length of the fetus reaches 50 cm, weight 2500-3500 g. During this period, final preparation for birth occurs. The fetal head descends into the mother's pelvis, which makes breathing easier and reduces pressure on the stomach. The parental canal expands, the cervix softens and contracts. As a result, a child is born.

It is important to understand that each fetus is unique and may develop differently. The development stages described above are common to most fruits, but may differ in specific cases. All changes occurring inside the uterus directly depend on the mother’s health, her diet, lifestyle and other factors. Therefore, it is important to lead a healthy lifestyle and monitor your health during pregnancy.