We just completed our first IVF/ICSI cycle (my husband's morphology is less than 2 percent) with no success. Eleven eggs were retrieved and 10 fertilized. Of those 10, two embryos reached the eight-cell stage at time of transfer, and the rest were at lower stages. Because of my age (30) we decided to only transfer the two eight-cell embryos. However, those two were not picture-perfect and had a lot of fragmentation. Why didn't all the embryos reach the eight-cell stage? What causes fragmentation? Did this have any bearing on why we weren't successful? What should our next step be?

L.N.

Embryo fragmentation may certainly be a factor in implantation failure. The more fragmentation seen, the poorer the embryo quality. Fragmentation is measured on a percentage scale; greater than 20 percent usually indicates a poor prognosis. The cause of fragmentation is not clear in most cases. It is believed to reflect chromosomal anomalies in the particular egg or sperm, but it may be related to laboratory conditions. Studies have also linked fragmentation to various factors in the stimulation treatment used before egg retrieval.

I would suggest you discuss the situation with your physician. In some cases where severe sperm abnormalities are noted, a chromosomal analysis of the male partner may identify problems. You may also want to discuss blastocyst transfer, which involves transferring the embryos at a slightly later stage of development. If the embryos are allowed to grow until the fifth day, the embryologist will better be able to determine which embryos will likely implant, thereby improving the odds for success.

The good news is that even though you were not successful this time, simply trying again may yield better-quality embryos and a better chance for success.