There is no such thing as a high success rate of heparin in preserving the fetus in a small gestational sac, heparin does not have a role in preserving the fetus, and pregnant women with small gestational sacs need to take general measures as well as medication to preserve the fetus according to the actual situation. Heparin is a common clinical anticoagulant, antithrombotic drugs, with inhibition of platelet aggregation, enhance vascular permeability, regulation of blood lipids and other effects, clinical mainly used in the treatment of eruptive purpura, amniotic fluid embolism and other diseases, and does not have the role of birth control. So there is no such thing as a high success rate of heparin in preserving the fetus with a small gestational sac. There are many reasons why a pregnant woman’s gestational sac is small, first of all, if the pregnant woman is due to her own menstrual cycle is longer, ovulation is late, resulting in late fertilization caused by the small gestational sac, generally do not need special treatment, the recent follow up with the doctor’s orders, observation of the body’s human chorionic gonadotropin level, progesterone levels, as well as fetal heart, fetal buds can be. Secondly, if the embryo is underdeveloped due to low progesterone level in the body, it can be treated with progestins such as oral dextroprogesterone and intramuscular progesterone under the guidance of the doctor to preserve the fetus. It is recommended that pregnant women with small gestational sacs first seek medical examination to clarify the specific causes of the disease, and then choose the appropriate medication for fertility preservation under the guidance of the doctor to avoid unauthorized use of medication.