Whether or not two blastocysts can be placed in the second transfer depends on the woman’s physical condition, for example, it is not recommended to place two blastocysts for women whose height is less than 145cm and cervical insufficiency, and two blastocysts can be placed for women who do not have any problems in all aspects. Women who are on their second transfer, but are usually healthy, relatively young, have not given birth, have no previous history of twin abortions, and have no scars on the uterus can have two blastocysts transferred in the uterine cavity in order to increase the success rate of IVF. Women who are less than 145cm tall, cervical insufficiency, previous history of twin miscarriage, hypertension during pregnancy, history of diabetes during pregnancy are recommended to transfer 1 blastocyst, these pregnant women have a higher chance of having a high risk pregnancy, and in order to minimize the impact it is not recommended to transfer two blastocysts. It is recommended that women go to the hospital for examination and let professional doctors decide how many blastocysts to transfer.