IVF / ICSI / IMSI are either cultured for 3 days or 6 days before transfer into the uterus (embryo transfer).
When embryos are cultured for 6 days then its called a Blastocyst transfer.
The goal of IVF/ICSI is to provide high-quality embryos which are capable of continued development and result in live births.However, under standard IVF/ICSI culture conditions, only about 25 to 60% of human embryos progress to the blastocyst stage after 5 days of culture.
At Indigo Womens Center we offer the highest success rates of blastocyst transfers in India thanks to our Embryologist team with over 35 years of synchronization with our reproductive medicine specialists.
The theory behind a blastocyst transfer is that, on day 5 post-conception, the endometrium is adequately receptive and the embryo should have moved into the uterus from the Fallopian tube.
By culturing embryos to day 5 we find most of the embryos do not move into the blastocyst stage.This gives us an opportunity to choose the most competent embryos for transfer. We can then transfer fewer embryos and still obtain high pregnancy success rates – with very little risk for having the high order (triplets or higher) multiple pregnancies.
Some patients have large numbers of frozen embryos and it can difficult to know which have the best potential for pregnancy. An option in these cases is to thaw all embryos and culture them through to the blastocyst stage to allow the best 1 or 2 embryos to be transferred depending on its development.
What are the cons of blastocyst transfer?
Sometimes when patients opt for a blast transfer, they might have a lower yield of embryos. This is because some embryos may stop their development at the 4- cell stage.
There is a remote chance that a single blastocyst can sometimes give rise to monozygotic twins.
Blastocyst transfer may not be suitable for older women because we expect a lower yield of oocytes.