The HCG doubling normal progesterone drop should be alerted to preterm abortion, and treatment to preserve the pregnancy is recommended. A normal pregnancy requires the maintenance of HCG, progesterone and estradiol, if one of these hormones is not up to standard, it may develop into preterm miscarriage or embryonic abortion, generally speaking, a normal doubling of HCG indicates that the embryo is developing well, and the pregnancy outcome is generally better through birth control, if the HCG doubles but the progesterone drops, it means that the luteal function may not be good, then it is necessary to supplement progesterone to protect the fetus, such as intramuscular injection If the HCG doubles but the progesterone decreases, it means that the luteal function may not be very good, so we need to take progesterone supplementation to protect the pregnancy, such as intramuscular injection or oral progesterone, generally 20 mg or 40 mg once a day, orally twice a day, two to four capsules each time, and also oral dydrogesterone tablets, once a day, one tablet each time. For HCG doubling normal progesterone decline must be actively fertility treatment, generally after a week to recheck HCG, progesterone, estradiol and ultrasound, if the indicators rise after the recheck is indicative of good embryo development, if not rise but decline to be alert to the possibility of embryonic abortion. In short, HCG doubled normal progesterone decline to timely supplement progesterone, keep a good attitude, do not be too nervous.