Study: Blastocyst transfer for repeated In vitro Fertilization - IVF failures

Last published / updated 02/08/2005An ongoing debate in the treatment of infertility is how to manage patients who have failed to conceive after multiple In vitro Fertilization - IVF failures. A recent study out of Spain, published in the medical journal Fertility and Sterility attempted to determine whether using blastocyst transfer may work better for these patients. Some Definitions:

Cleavage stage embryo: An embryo which has begun to divide. Cleavage stage transfers are typically performed on the third day after egg retrieval. This is known as a Day 3 transfer

Part of the problem with cleavage stage embryos is that it is more difficult to determine which ones have the greatest likelihood for implantation. Even if they look healthy under a microscope, they may not develop well after the third day. To compensate for this shortcoming, in vitro Fertilization - IVF programs will increase the number of embryos they place in the uterus. This will occasionally work but it also increases the chances for a multiple pregnancy. By waiting for 5 or six days, the in vitro Fertilization - IVF laboratory staff can better pick those embryos which are likely to produce a pregnancy. Typically, less embryos are required and this will also reduce the multiple pregnancy rate. In this recent study, the researchers identified 148 women who had failed to conceive after at least three in vitro Fertilization - IVF failures. The patients underwent another In vitro Fertilization - IVF attempt but this time planning to use blastocyst transfer. They compared the pregnancy rate for patients who had > blastocysts develop by Day 5 to those in which > blastocysts developed only by day 6.91% of the patients had at least one blastocyst to transfer and 73% had at least two. For those patients who had Day 5 > blastocysts, the pregnancy rate was 38%. For those who had a day 6 transfer, the rate was only 11%What does this study show? Well, you could conclude the doing a > blastocyst transfer is a reasonable treatment option even for women with repeated in vitro fertilization - IVF failures. We

cannot

say that doing a blastocysttransfer would have worked better than simply performing another cleavage stage transfer because there was no cleavage stage control group. A major shortcoming of this study. We can also state that at least in patients with recurrent in vitro fertilization - IVF failure, that a Day 5 transfer seems to work better than a day 6 transfer. As far as studies go, this one is pretty weak.