HCG also rises on the 26th day of blastocyst transfer. Accompanied by the implantation of blastocysts, HCG in the blood of pregnant women grows gradually, reaches its peak at 8-10 weeks of pregnancy, then remains sluggishly until the 12th week, and in the middle and late stages of pregnancy the HCG markers in the blood fall to 10% of the maximum value. That’s why 26 days after the transfer of blastocysts HCG is still elevated. HCG in the blood is maintained at a certain level to ensure that the corpus luteum of pregnancy does not decline and maintains the growth and development of the IVF embryo. If HCG is low, it may affect the growth and development of the IVF embryo and lead to miscarriage and other adverse pregnancy outcomes. Pregnant women should strengthen nutrition, pay attention to rest, ensure enough sleep, and maintain a good mood, which is conducive to the development of the fetus.