Blood circulation. During pregnancy, the volume of blood circulation increases significantly. This is how the body prepares for possible excessive blood loss during childbirth. By 27-28 weeks of pregnancy, blood circulation increases by 50%. The number of red blood cells and hemoglobin decreases slightly, and the hemoglobin content in the blood decreases. Respiratory organs. As the baby grows, the diaphragm moves upward, restricting the excursion of the lungs, causing a feeling of discomfort, a feeling of false respiratory failure. The chest expands by 4-5 cm. Urinary organs. Due to the increase in blood volume, the kidneys work with tension. As the baby grows, the urge to urinate will become more frequent, and more frequent urination at night often occurs. By the end of the day, due to the vertical position of the body, fluid accumulates in the lower extremities; after rest, during the physiological course of pregnancy, the swelling disappears. Digestive organs. As a rule, appetite increases. Some women have a special craving for certain dishes (often salty, sour). The intestines work with less activity, and constipation often occurs. Skeleton. The joints of the pelvic bones soften under the influence of hormonal changes. This makes labor easier, but later in pregnancy it makes walking difficult. As pregnancy progresses, the center of gravity moves and a “duck walk” occurs. Nervous system. During pregnancy, mood swings appear and sensitivity increases. This can be explained by hormonal changes. Skin. Pigmentation often occurs on the face, in the area of ​​the areola, and the white line of the abdomen. Pigmentation is associated with hormonal changes, and after childbirth, age spots disappear. Many women are bothered by stretch marks that appear on the stomach, chest, and less often on the hips and buttocks. After childbirth, these reddish stretch marks do not completely disappear, but turn into silvery lines. Tingling, slight itching of the skin occurs as a result of increased sensitivity of the nerve endings. Breasts. The mammary gland increases during pregnancy and by the end of pregnancy its weight is about 1 kg. Sensations change when touched. Veins become more visible under the skin. Sometimes a thick, creamy liquid called colostrum is released from the nipple. It should be removed with clean warm water. Uterus. At the time of conception, the uterus is a hollow organ weighing about 50-60 g, located in the pelvis. With the beginning of pregnancy, the uterus grows, after the 12th week it is located in the abdominal cavity above the womb and by the end of pregnancy its weight reaches 800-1000 g, length 50 cm. It contains the fetus, connected by the umbilical cord to the placenta (the organ through which nutrition is provided and breathing of the intrauterine fetus), and amniotic fluid (about 1.5 liters).