There are many reasons for the doubling of HCG (human chorionic gonadotropin) at the beginning, and then the poor development, the main reasons include abnormalities of the reproductive immune system, chromosomal abnormalities, abnormalities of the uterine cavity, and the influence of environmental factors. 1. Abnormalities of the reproductive immune system: the occurrence of the corresponding conditions, along with the occurrence of perverse reactions, will affect the stability of the embryo, and further cause pre-eclampsia caused by the corresponding changes. 2. Chromosomal abnormality: the chromosomal abnormality of the embryo itself will cause unstable growth and development, and further spontaneous abortion, causing corresponding conditions. 3. Abnormalities in the uterine cavity: unstable uterine cavity, especially the endometrium is not tolerant, which will affect the stability of the embryo and cause corresponding conditions. 4. Influence of environmental factors: the influence of trauma or physical and chemical factors can also cause unstable development of embryo and lead to the corresponding conditions. Abnormal embryonic development, accompanied by obvious abdominal pain and bleeding, need to consult a doctor in time to confirm the specific physical condition, and under the guidance of the clinician to carry out standardized treatment, to avoid causing delays in the condition.