At the end of the 1st obstetric month of pregnancy (4 weeks), the size of the uterus reaches approximately the size of a chicken egg. At the end of the 2nd obstetric month of pregnancy (8 weeks), the size of the uterus approximately corresponds to the size of a goose egg. At the end of the 3rd obstetric month (12 weeks), the size of the uterus reaches the size of the newborn’s head, its asymmetry disappears, the uterus fills the upper part of the pelvic cavity, its bottom reaches the upper edge of the pubic arch. Starting from the 4th month of pregnancy, the fundus of the uterus is palpated through the abdominal wall, and the duration of pregnancy is judged by the height of the fundus of the uterus. It should be remembered that the height of the uterine fundus can be affected by the size of the fetus, excess amniotic fluid, multiple pregnancies, abnormal position of the fetus and other features of the course of pregnancy. Therefore, the height of the uterine fundus when determining the gestational age is taken into account in conjunction with other signs (date of the last menstruation, first fetal movement, etc.).