A blastocyst is an embryo that consists of more than 100 cells. It is at the blastocyst stage of development (5 days after fertilization) that an embryo would normally move out of the fallopian tube and into the uterus. Once in the uterus, the blastocyst starts to attach to the uterine lining in a process known as implantation. Using newly developed culture media, we are now able to select embryos that will remain healthy in culture in the laboratory to the blastocyst stage prior to transfer. A higher implantation rate has been observed following transfer of blastocysts (50%), by some scientists. Our experience shows that the success of transfer depends on whether the uterine lining is ready to receive the embryos rather than the stage at which the embryos are transferred.

We achieved the first pregnancy in India using the technique of Laser Assisted Hatching and Blastocyst Transfer (LAHBT).