What is a blastocyst?
Embryos can be cultured in the lab for up to 5-6 days, when provided with good nutrition in terms of media and environment. Such cultured and grown up embryos are called as blastocysts. Since the blastocysts have made it through the key growth process, they offer a greater chance of successful implantation and pregnancy.
One of the biggest challenges in IVF is the ability to select and transfer an embryo with the best implantation potential and highest probability of resulting in a pregnancy. The traditional practice to achieve a higher probability of implantation and pregnancy has been to transfer more than one embryo in the uterus on the 2nd or 3rd day of development. Blastocyst culture is a better alternative to achieve the same objective, as it allows us to grow the embryos in laboratory for a few extra days, after which the best quality grown up embryo (called as a blastocyst) can be transferred into the uterus. Such selection enhances the chances of implantation and improves the chances of achieving pregnancy without putting the woman at risk of multiple pregnancies and its complications such as prematurity, IUGR and foetal loss.
However, blastocyst culture is a not a suitable technique for all patients. This technique is not so useful especially in cases where a fewer number of eggs are retrieved or a fewer no of embryos are formed. In such cases, additional embryo culture in laboratory will not improve the pregnancy rate. Therefore we always discuss this option with our patients in conjunction with our embryologist in order to evaluate the pros and cons of blastocyst culture for a particular case/ situation and then individualize the decision to each case.