DNA damage in sperm – what are the implications for IVF outcomes?

This study investigated if sperm DNA fragmentation (SDF) has an effect on fertility outcomes (FOs).

They found that high SDF was linked to poor embryo development (ED) and negative FOs.

Male infertility is measured using a number of criteria. Sperm count and quality are assessed. The shape or morphology of sperm can also indicate how fertile a man is. Male infertility may contribute to up to 50% of infertility cases. However, 15% of men have ‘normal’ sperm criteria and still cannot conceive. Some studies suggest that sperm DNA fragmentation (SDF) may explain ‘unknown infertility’ in men. 

DNA fragmentation can only be detected using a specific test. It there are breaks in the DNA strand, sperm can still fertilize an embryo. However, the quality of the embryo may be affected by SDF. SDF can result in a little or a lot of DNA damage. It is unclear if SDF has an effect on fertility outcomes (FOs) after assisted reproduction (AR). 

This study included data from 475 AR cycles. Intracytoplasmic sperm injection (ICSI) is an AR technique. It involves fertilizing an egg with sperm in a lab setting. The couples were undergoing ICSI for female-related infertility. SDF was measured from sperm samples. The level of SDF was categorized as below 30% (SDF30-) or 30% and above (SDF30+). FOs were compared between the groups. They included implantation rate (IR) and miscarriage rate (MR). Embryo development was also assessed.

Couples with SDF of 30% or more had slower embryo development. The number of high quality embryos was lower in SDF30+ couples. Other ED parameters were also poorer in SDF30+ couples. IR was significantly lower in SDF30+ couples. Pregnancy rates were similar between the groups. The MR was 2.5 times greater in SDF30+ couples.

The authors concluded that high SDF was linked to a poor embryo development and negative FOs.

The number of patients in the study was small. The SDF measurement was open to variability. More stringent tests could be used in future studies. 

If you have any concerns regarding infertility, please consult with your doctor.