The normal value of progesterone in the fourth week of pregnancy is about 20ng/mL, which varies from person to person, and also fluctuates up and down on the same day for the same person, so you can’t judge the development of the embryo purely on the basis of the value of progesterone. After pregnancy, progesterone value will gradually rise, generally 20-42ng/ml in early pregnancy, 42-120ng/ml in mid-pregnancy, 120-240ng/ml in late pregnancy. Progesterone is a hormone secreted by the corpus luteum of the ovary and is one of the hormones necessary to maintain pregnancy. In early pregnancy, progesterone is mainly secreted by the corpus luteum of pregnancy, while when the placenta is formed, it is mainly secreted by the trophoblastic layer of the placental commissure, and the level of progesterone will rise to 100-200ng/ml. There are differences in the value of progesterone in different periods of a woman’s life and it cannot be generalized. The reference values of progesterone in pregnancy are as follows: 24.5±7.6ng/ml at 7 weeks of pregnancy, 28.6±7.9ng/ml at 8 weeks of pregnancy, 38.0±13.0ng/ml at 9-12 weeks of pregnancy, 45.5±14.0ng/ml at 13-16 weeks of pregnancy, 63.3±14.0ng/ml at 17-20 weeks of pregnancy, 110.9±35.7ng/ml at 21-24 weeks of pregnancy, and 165.3±35.7ng/ml at 25-34 weeks and 202.0±47.0ng/ml at 35 weeks of gestation. Regular checkups are needed during pregnancy, and progesterone is only a reference indicator, which should be combined with ultrasound and other examinations to comprehensively assess the growth and development of the fetus. null null null