HCG refers to human chorionic gonadotropin, which is usually elevated in the mother’s body at the same time as progesterone during pregnancy. If HCG doubles and progesterone decreases during pregnancy, it may be a normal physiological phenomenon or caused by pathological factors such as luteal insufficiency, which needs to be analyzed according to the situation and then treated for specific reasons. Common causes and treatment measures 1, normal physiological phenomenon: progesterone is mainly secreted in a pulsatile manner, and there will be large fluctuations in early pregnancy. Therefore, if progesterone is lower than 15ng/mL for one time during peripheral blood sampling, it may only be a temporary decrease in progesterone. At this time, if the pregnant woman does not have symptoms of pre-miscarriage such as vaginal bleeding, abdominal pain, lower abdominal cramping, etc., and the serum HCG is normal, it can be observed first without special treatment; 2. Luteal insufficiency: If the progesterone drops in several examinations, there may be luteal insufficiency, the ovaries do not fully form the corpus luteum after ovulation, resulting in insufficient secretion of progesterone, which affects the endometrial conversion and is not conducive to the fertilization of the egg. . Vaginal bleeding or subchorionic hematoma may occur, which requires prompt medical treatment and the administration of natural progesterone under medical supervision to prevent preterm abortion. Pregnancy should not only depend on the progesterone HCG value, but also on the estradiol value and ultrasound to see the development of the fetus, if necessary, under the guidance of a doctor.