A double bar measured at 3 days after transferring a blastocyst is not necessarily a success, and further blood HCG and ultrasound are needed to identify it.
Transplantation of blastocysts three days to detect a double bar suggests that the HCG level in the urine is elevated, but the cause of the elevated HCG level is not necessarily a normal pregnancy, and there may be other diseases that lead to elevated HCG levels. If the blood test suggests elevated HCG levels, and ultrasound is performed one week later, if the image of the embryo can be seen in the uterine cavity, it suggests that the transfer of blastocysts has been successful.
Ectopic pregnancies can also show two bars due to elevated HCG levels, but the ultrasound cannot see the gestational sac in the uterine cavity, but rather in the fallopian tubes or elsewhere, which requires surgical intervention. Biochemical pregnancies may also show two bars, but later in life the HCG levels will drop and the gestational sac will not be detected on ultrasound.
Other pregnancy-related trophoblastic diseases, such as hyperemesis gravidarum, will show two bars on the test, and the HCG level will be significantly higher than the corresponding gestational week, but the normal gestational sac can not be seen in the uterine cavity, but rather a honeycomb or snow-like tissue, which also requires surgical treatment.
When two bars are detected three days after the transfer of blastocysts, you need to go to the hospital as soon as possible for blood HCG and ultrasound examinations to determine the results of the transfer.