Male infertility is a very common condition, with reports suggesting that one in 15 men of reproductive age are affected. The diagnosis of male-factor infertility is difficult and involves discounting female infertility through hormone measurements, pelvic examination and invasive laparoscopy. A semen profile analysis can suggest male infertility, if sperm counts are <15-20 million/ml, or <50% of sperm possess forward progressive motility (and < 25% rapidly progressive sperm) or <4% good morphology sperm. However, the diagnostic potential for a semen analysis is is has been questioned by many reports (1-5).
We have used non-selected, sperm samples from a population of males attending infertility clinics with suspected infertility (asthenozoospermic, teratozoospermic, asthenotetatozoospermic and normozoospermic idiopathic) and performed a quantitative proteomic analysis. Within this analysis, several antimicrobial pre-cursor proteins were found to be vastly up-regulated within the infertile sperm population. Such proteins are cleaved into peptides, which we have now shown to be toxic toward spermatozoa. A novel model of male infertility will be presented and a possible approach for better sperm selection for ART presented.