Effect of sperm DNA fragmentation on embryo quality

Hey, can you help us? This is our 2nd cycle and the semen analysis carried out on my husband keeps on showing sperm DNA damage from the beginning. Doctor told us this is the reason why the quality of our embryos for IVF is too low, but we don’t actually understand why or why is it related to embryo quality. We’re sorry for being ignorant, but there’s not much we understand here, further clarifications are needed. Thank you very much!!

Dear OmegaΩ,

Indeed, sperm quality is directly linked to poor embryo quality, in particular the degree of DNA fragmentation in the sperm. In other words, the percentage of normal sperm with fragmented DNA is negatively correlated with embryo quality and pregnancy success rates.

As shown in a study conducted by researchers from the July 2010 issue of the magazine Fertility & Sterility, when the percentage of sperm with fragmented DNA is less than 17.6%, pregnancy success rates are 3.5 times higher. This means that DNA fragmentation of morphologically normal sperm negatively impacts embryo quality and, subsequently, odds of achieving pregnancy.

Sperm DNA fragmentation refers fundamentally to what percentage of sperm have fragmentation, that is, how many sperm are “damaged”. For instance, less that 15% damage is an indicator of a very good outcome, whereas 16-29% may indicate less chances of getting pregnant. If more than 30% of sperm show DNA fragmentation, then achieving pregnancy and maintaining it a healthy one could be pretty difficult, even in cases of IVF.

You should keep in mind that DNA damage increases with age; thus, a man in his 50s or even 60s may have a higher percentage of sperm DNA fragmentation than a man who is 30 years old or younger. Other factors promoting DNA damage are: excessive heat, chronic infections in the prostate, chemotherapy, radiation, smoking, or exposure to certain chemicals or toxic agents. The good news is that antioxidant vitamins can help minimize the damage this may cause.

This article may be of interest to get further details: Sperm and antioxidants.

Hope this helps,

Regards