DNA fragmentation test

The methods for evaluation of male infertility have typically been limited to a semen analysis measuring count, motility and morphology of the sperm. When it comes to sperm quality, conventional semen analysis (SFA) tells us little. The Sperm DNA Fragmentation test is a much more sensitive male fertility test that can measure DNA damage in individual sperm.

Why we cannot rely completely upon conventional SFA?

* A normal spermiogram does not necessarily correlate with fertility potential
* SFA does not assess sperm function
* There is a significant proportion of patients with normal SFA showing unexplained infertility
* There is a significant overlap between fertile and infertile men with respect to sperm concentration motility and morphology
* There are a subset of patients in whom the standard semen analysis has been unable to detect some functional deficiency necessary for fertilisation, estimated at 40% of men presenting for subfertility
* SFA claimed to be poorly standardised, subjective and not powerful predictors for fertility
* There is evidence to suggest that infertile men possess substantially more sperm DNA damage than fertile men
* The association between sperm DNA damage and the traditional semen parameters is only weak to moderate

The Principal of Sperm DNA Fragmentation

The development of a healthy embryo is initiated when the chromosomes from the female (in the egg) come together with chromosomes from the sperm. These chromosomes consist of strands of DNA (deoxyribonucleic acid). These strands of DNA can become damaged. Sperm DNA fragmentation is expressed as a rupture of DNA strand in both or just one DNA helix. If the rupture affects genes which are vital for embryo and implantation development then during some stage the embryo may not survive.

New studies suggest that sperm with certain levels of DNA fragmentation serve as a strong predictor of reduced male fertility.

Research indicates that sperm with high-levels of DNA fragmentation have a lower probability of producing a successful pregnancy. A review of data on hundreds of semen samples show that patients with a DNA fragmentation level of greater than 20-30% (depending on the technique used) are likely to have significantly reduced fertility potential, including a significant reduction in term pregnancies and a doubling of miscarriages.

Sperm that appears to be normal by traditional semen analysis parameters (motile, morphologically normal sperm) may even have extensive DNA fragmentation.

Possible causes of DNA fragmentation:

* Drugs, chemotherapy & radiation therapy
* Cigarette smoking, environmental toxins & air pollution
* Genital tract inflammation
* Testicular hyperthermia (use of hot baths, saunas, laptop computers & prolonged periods of driving
* Nutrition
* Varicoceles
* Hormone factors
* Infrequent ejaculation
* Male’s age

DNA fragmentation test is recommended for patients with:

* Unexplained Infertility
* Cessation of development of embryo in previous IVF/ICSI cycle
* Poor blastocyst development in previous IVF/ICSI cycle
* Previous IVF/ICSI failure
* Varicocele
* Repeated miscarriage
* Cases that have any of the causes of DNA fragmentation
* Cases that which to optimise their chances before IVF/ICSI