Blastocyst transfer allows embryos to develop for longer outside the womb, reaching the ‘blastocyst’ stage before being implanted and increasing the chance of successful implantation. If you’ve produced good quality embryos in previous cycles but had issues with implanting in the womb, then blastocyst transfer could be right for you.
What is a blastocyst?
What is a blastocyst transfer?
What should an embryo do after transfer?
As the embryo develops into the blastocyst stage (late day 4 onward), it needs to escape the "shell" that once protected it. The blastocyst continues to fill with fluid and weakens the shell. Eventually the blastocyst hatches out of the shell (pictured) and is ready to implant into the lining of the uterus. This is thought to happen around 7-8 days post insemination.
Could it be right for me?
Why blastocyst transfer?
Selection of embryos
We know that at least 50% (or higher in women over 40) of embryos are not viable, and many of these embryos stop developing before day 5 or 6. A large proportion may have an incorrect number of chromosomes and it is believed that those embryos which failed to develop to day 5 or 6 would not, in any event, have established a pregnancy. Where there are large numbers of good quality embryos available at the blastocyst stage these can be frozen. We have seen excellent post-thaw survival and pregnancy rates with frozen blastocysts.
Research has shown that conditions in the womb may be more optimal for a blastocyst implantation than a day 2/3 embryo as there are slightly differing conditions in the fallopian tube and the womb.
Higher chance of a successful pregnancy
Data suggests that blastocyst transfer can increase the chances of a live birth. Please bear in mind that every one is an individual and your consultant or embryologist will advise on which approach is best for you. View our clinic success rates.
Frozen embryo transfer
Some patients have a high number of frozen embryos and one option is to thaw all embryos and culture through to the blastocyst stage to allow the best 1 or 2 embryos to be replaced based on their development. Please remember that the extended culture process doesn't enhance an embryos quality per se, it is a way of choosing the most viable from a group of embryos.