In daily life, for early pregnancy with a small amount of vaginal bleeding, especially difficult to conceive and IVF pregnancy hard-won pregnant women, once the signs of preeclamptic abortion, but also like a big enemy, desperately using a variety of measures for all-around birth control, progesterone dosage again and again and again, the pregnant woman and her family members are doubly stressed, agitated and uneasy. Pregnancy lasts, they think they have the right method, widely publicized in the patients, and eventually miscarried, will find various reasons to regret. Is it really possible to keep a miscarriage? Is the child that is “saved” necessarily better? We know that in early pregnancy, the ovaries on the corpus luteum secretion of progesterone, estrogen through the uterine membrane support, and reduce the sensitivity of the uterine smooth muscle, inhibit uterine contraction and thus maintain pregnancy. At the same time, progesterone also has an immune effect, can be directly involved in the maternal-fetal interface immune response, to promote maternal-fetal tolerance and prevent miscarriage. The corpus luteum in the state of pregnancy at 7 to 9 weeks of gestation, the placenta replaces the corpus luteum to produce estrogen and progesterone, realizing the luteal body and the placenta’s functional conversion and handover. Whether it is natural conception or ovulation line assisted reproduction treatment conception, 20-30% of the population in the early stages of pregnancy, a small amount of vaginal bleeding and other symptoms of aura of miscarriage, 10-20% of the miscarriage will occur, which only a very small number of people with chromosomally normal embryos, is due to maternal luteal insufficiency caused by miscarriage, this type of patient using luteal support therapy to preserve the fetus efficacy of the treatment is obvious; genetics point of view, there is at least 50% of the Genetically, at least 50% of miscarriages are caused by embryonic factors, i.e., the embryo is abnormal, and the miscarriage is a process of natural elimination; such miscarriages are ineffective when treated with progesterone, which can only delay the time of the miscarriage. In addition, even if the luteal support is effective, in accordance with the laws of nature, the use of progesterone to the 70th day of pregnancy can gradually reduce the dosage, so that the placenta to replace the function of gestational luteinization, rather than luteinization the longer the better, not the more the better the use of progesterone.