Human embryos from in vitro fertilization in culture in an IVF lab usually reach blastocyst stage by day 5 after fertilization. Blastocyst is an embryo which has developed to day 5 stage with different cell components and a fluid cavity. At blastocyst stage of development, the embryo must reach before it can implant in the uterus.These embryos have the best potential for implantation.
Is blastocyst good for couples undergoing IVF ?
In IVF & ICSI procedures oocytes are taken outside and good and mature oocytes are fertilized with sperms and the developing embryo is transferred on day 3 or day 5 according to the implantation rate. Compared with day 3 embryo day 5 embryo has high implantation rate because on day 5 embryologist can pick the best grade embryo and best grade embryo will be transferred and get implanted.