How many days after cystocyst transfer implantation

When there are many cases of infertility between men and women, artificial insemination is adopted, which is what we often call test tube babies. This method of pregnancy is very desirable, and the children bred by test tube babies are generally smarter, because in the selection process, sperm and eggs are the most common ones. So how many days will it take for the embryo to implant in the female uterus after transplantation?

Blastocyst transfer is a type of IVF embryo transfer that can increase the IVF embryo implantation rate while reducing the possibility of multiple pregnancies. The in vitro fertilization blastocyst transfer technology imitates the rules of natural pregnancy. When the embryo develops into the blastocyst state, the blastocyst is transplanted into the mother's uterus. This can increase the success rate of in vitro fertilization and reduce complications. The success rate of IVF blastocyst transfer is about 20% higher than that of ordinary transfer.

The cultivation of sperm and eggs for in vitro fertilization is very critical, and the operation of egg retrieval is much more complicated than that of sperm retrieval. In clinical practice, sperm extraction should be performed based on the results of sperm testing. If the sperm motility, morphology, especially the ability of sperm to adhere to and penetrate the zona pellucida and fuse with the egg membrane are normal, IVF in vitro fertilization can be used. The sperm and egg can be placed in the same constant temperature incubator to allow the active sperm to freely combine with the egg. If a man's sperm is weak or low, or he has certain infectious or genetic diseases, he will need to use ICSI. First, the sperm will be cleaned through sperm washing technology, and then the sperm with normal DNA will be selected and directly injected into the egg to fertilize the egg.

After the sperm breaks through the zona pellucida of the egg, if two pronuclei can be seen under the microscope, it means that the sperm and egg have successfully combined, and the embryo cultivation stage has begun.

Division of the fertilized egg

The fertilized egg grows in a culture dish where the temperature, concentration and humidity are similar to those of the uterine environment. On the second day, it will divide into a 2-4 cell embryo. On the third day, the cells continue to divide and grow to 6-8 cells. At this time, it can be upgraded to a morula and become an "embryo" in the terminology of in vitro fertilization. Usually at this time the doctor will grade the embryo based on its division and growth, and make a judgment based on the growth rate and the degree of balance in cell size.

A good embryo will continue to divide and grow, forming a blastocyst on the fifth day, at which time it will generate about a hundred cells. If everything is fine in terms of morphology and development, the next step is PGD genetic screening to detect whether the blastocyst carries chromosomal diseases and recessive genetic diseases. PGD ​​technology can screen for 125 diseases including Emrys-Dreyfus muscular dystrophy, myotonic dystrophy, and neuroaxonal dystrophy. After the screening, the transplantation stage can be entered.

Blastocyst transfer

After the blastocyst passes the test, the doctor will use a very thin and soft tube to transplant it into the uterus. This process is completely painless. The entire embryo transfer process will be carried out under the monitoring of B-ultrasound. The fertilized egg is surrounded by a thin protective layer, the zona pellucida. Within 4-5 days after implantation in the uterus, the fertilized egg will release an enzyme and bury itself in the uterus. Life will emerge from this "zona pellucida" and implant in the uterus. Everything after that is just like a natural pregnancy.

Therefore, within 48 hours after embryo/blastocyst transfer, patients are generally required to stay in bed as much as possible and avoid excessive movements and exercise. At this time, the embryo/blastocyst is still unstable and requires a relatively stable environment to help them take root and grow.

For some patients, the fertilized egg will implant and develop around 3-4 days after transplantation, but for some patients it will be relatively later. Experts recommend that patients come to the hospital 14 days after the embryo is transplanted to confirm whether the pregnancy is successful through examination.