Blastocyst stage transfer:

A blastocyst is an embryo that has developed for 5 to 6 days after fertilization and then layers of cells start to differentiate. Now it is ready for implantation into the uterine wall (endometrium).

Individual factors are often important in making this decision, such as:

• Increased pregnancy rate
• Age of the female partner
• Information from previous IVF cycles
• The planned number of embryos to be transferred to the uterus (1or 2)
• Whether preimplantation genetic screening is desired by the couple