Should I have a Day 3 embryo transfer or a Day 5 (blastocyst) embryo transfer?
Recent advances in the laboratory has led to the development of new culture systems capable of growing embryos beyond the Day 3 stage and to the Day 5 or blastocyst stage. This is achieved by using not one, but a sequence of culture media, each designed to meet requirements specific to each preimplantation stage. The availability of a number of successful sequential culture systems has led many programs of assisted reproductive technology to pursue blastocyst production and replacement. The principal indication for Day 5 or blastocyst transfer is the reduction of ART-associated multiple pregnancy. Approximately 40% to 60% of fertilized oocytes reach the blastocyst stage using contemporary sequential culture systems, but there are remarkable variations a patients ability to produce blastocysts. A risk of attempting blastocyst transfer is the possibility that no embryos will be available for replacement. It is best to check with your individual clinic to assess the availability of and th
