DNA Fragmentation: The danger we don't know enough about

A high sperm count, combined with good motility (swimming ability) and morphology (sperm shape), ought to indicate healthy degrees of fertility in men.

Unfortunately, they don’t – not when DNA Fragmentation is also taken into consideration.

While the term looks as though it belongs as part of the regular maintenance of a person’s computer drive, the impact DNA Fragmentation has on couples’ chances of conceiving is far more serious than that. In fact, a high amount of fragmented DNA can result in reduced male fertility, subpar embryo development, and less successful rates of implantation.

While all of the causes of DNA Fragmentation are not yet known, some that are include age, smoking, infection, testicular cancer, heat exposure, and toxin/chemical exposure.

Healthy DNA is distinguished by a double-helix spiral held together by cross-bonds that together appear to form a ladder shape. However, once any of the “rungs” become broken or unstable, the whole ladder becomes unsteady. The result: DNA Fragmentation, which leads to chromosomal abnormalities, which contribute to birth defects.

What’s more, DNA tends to progressively break down as a person ages, which indicates that the chances of fragmented DNA become greater the older a man gets. In fact, a recent New York Times article quoted fertility expert Dr. Paul Turek as saying just that. This, in turn, is believed to lead to higher rates of infertility or miscarriage.

A 2018 study published in the Middle East Fertility Society Journal further examined the role that fragmented DNA plays in recurrent pregnancy loss (RPL), which involves two or more failed pregnancies.

Researchers conducted a 2-year retrospective look at 149 couples, 67 of whom had partners who were healthy and with “normal karyotype,” which refers to the number and appearance of the chromosomes present in a cell. The study found that “cytogenetic abnormality [chromosomal defect] is one of the most common causes of recurrent fetal loss”.

The study also confirmed that 75% of the sperm samples from couples experiencing RPL demonstrated good sperm count, motility, and morphology which, the authors said, “drives home the limitation of routine semen examination in detecting sperm defect abnormalities”. The study concluded that testing for “sperm DNA integrity” could prove “valuable” for helping RPL couples.

Exactly how valuable, though, remains unclear. In a 2017 study entitled Finding the fit: Sperm DNA integrity testing for male infertility, the aforementioned Dr. Turek examined the semen analysis test that is often used to evaluate male fertility.

He concluded, “the concept that fertility is defined by threshold values of semen parameters is fundamentally flawed”.  In particular, he noted, tests to determine sperm DNA fragmentation led to results that were “nothing to brag about”. He further suggested that only time and more study will tell us “where sperm DNA integrity testing fits into the male infertility diagnostic algorithm”.

But while resoundingly conclusive answers about the ability to DNA Fragmentation have yet to be presented by the scientific community, it remains well known that, as previously stated, fragmentation leads to complications, including miscarriage and infertility.

Rather than wait for a definitive test, it stands to reason that men should take steps that can reduce the effects of DNA Fragmentation.

These include curtailing or eliminating negative behavioral habits, such as smoking, drinking, and needless exposure to toxins and pollutants. And, according to a leading fertility clinic in the U.K., men should also strive to eat a balanced diet; naturally occurring antioxidants appear to help in battling DNA Fragmentation, though medical antioxidant treatments have not thus far proved effective.

A 2009 study published by the European Society of Human Reproduction and Embryology (ESHRE) suggests that men who have daily sex can reduce sperm DNA damage.

A 2013 study, though, suggests that having sex each and every day might not be as effective in reducing sperm DNA Fragmentation as creating a schedule that includes an abstinence day. Researchers writing in the Journal for Assisted Reproduction and Genetics concluded that just one abstinence day resulted in a reduction of sperm DNA Fragmentation in 90% of the subjects tested.

Above all, though, the most effective way to combat the known and unknown effects of DNA Fragmentation is to take early, proactive steps to protect your assets before the process of degradation can be permitted to cause irreparable damage.

The ever-aging “ladder” ensuring the integrity of sperm DNA is only as strong as the youthful “rungs” that comprise it.