The transfer here refers to in vitro fertilization embryo transfer, the HCG range of 16 days after the transfer is around 500-600mIU/mL, the HCG reference value is greater than 400mIU/mL is normal, simply a blood test can not judge whether the embryo development is good or not. Early pregnancy needs to dynamically observe the doubling of HCG value, the transferred embryo is the blastocyst on the 5th~7th day, the HCG value on the 14th day after the transfer is usually more than 300mIU/mL, doubling is more than 200mIU/mL in 2 days, and the checking of HCG on the 16th day is roughly in the range of 500-600mIU/mL. Simply a blood test, the value of the test can not intuitively understand the development of the embryo in the uterus, HCG doubling every other day means that the development of the embryo is normal, every other day, if it does not double or rise is not good, it may be an ectopic pregnancy, embryonic development abnormalities caused by the need for further examination to determine the cause. Women should pay more attention to rest after the implantation, and do obstetric examination regularly after the implantation to determine whether the embryo is developing normally.