Hubby Dear, Your Clock is Ticking, Too!

It is well known that women experience a ticking clock towards infertility in the ages forty to fifty. Less realized is that men also have a ticking clock even though they may have a normal semen test. Forty years ago, I invented the concept of sperm DNA fragmentation, i.e. broken sperm DNA, as one cause of male factor infertility, along with the first DNA fragmentation test, the Sperm Chromatin Structure Assay, or SCSA. We have just published a study on 25,000 men attending infertility clinics showing the relationships between the age of men and the extent of sperm DNA damage. When men have more than about 25% of their sperm with broken DNA, pregnancy attempts by intercourse and IUI have significantly reduced odds of success. Such couples are often counseled to use ICSI fertilization at infertility clinics for increased odds of pregnancy success. Men in their 20s typically have less than 10% of sperm with broken DNA. However, our current study shows that men aged 40 and 50 have, on average, a 20% and a 40% chance, respectively, to be at the threshold of 25% DFI by age factor alone. So, a man who was fertile at a young age may be infertile at an older age due to damaged sperm DNA. Higher levels of DNA fragmentation may also lead to increased odds for miscarriage. A healthy egg can repair sperm DNA damage after fertilization but there is a limited capacity for fixing sperm with a high level of DNA damage. Lifestyle and medical factors such as poor nutrition, smoking, obesity, cancer, chemotherapy, testicular varicocele and environmental pollution are related to increased sperm DNA fragmentation. Reduction of these factors can improve sperm DNA integrity.