One of the misconceptions about fertility treatment in our book, "Conceptions & Misconceptions" is the notion that "more is not necessarily better; better is better." In other words, quality is more important than quantity. This is especially important when considering embryos.
When a couple ends a cycle with poor quality embryos the focus is usually on the eggs. But now there is more focus on sperm quality as a cause of poor embryo quality, specifically the degree of DNA fragmentation in the sperm. In an article in the July 2010 issue of Fertility & Sterility the percentage of normal sperm with fragmented DNA (normal SFD) was correlated with embryo quality and pregnancy outcomes.
A highly statistically significant negative correlation was found between the percentage of normal sperm with fragmented DNA (SFD) and embryo quality. When the percentage of SFD was less than 17.6 %, the likelihood of pregnancy was 3.5 times higher. The authors concluded that the DNA fragmentation of morphologically normal sperm negatively impacts embryo quality and probability of pregnancy in ICSI cycles.
This is an issue that we have been looking at for some time, performing a Sperm Chromatin Structure Assay (SCSA) when couples have experienced repeated IVF failure, especially associated with poor embryo quality. Strategies to reduce DNA fragmentation include lifestyle changes when appropriate, antioxidant vitamins, shorter intervals of ejaculation prior to the IVF specimen and in rare cases, obtaining sperm by testicular biopsy (TESE).