Extensive discussion of male factor infertility is within Section: Endocrinology of the Male edited by Robert MacLachlan,M.D (www.endotext.org). A recent study performed by the Reproductive Medicine Network correlated semen parameters to fertility. The "new norms" by which fertility can now be defined are: a sperm density greater than 13.5 million/ml, motility greater than 32%, and a strict morphology greater than 9% (43). Abnormal semen parameters have a host of causes ranging from an absent vas deferens secondary to cystic fibrosis heterozygosity to a varicocele. Nonetheless, when the semen parameters are low, the number of competent sperm available to fertilize an oocyte is decreased and the monthly fecundity is lowered.It is more difficult to explain why male factor infertility occurs in the presence of normal semen parameters. Some have suggested that abnormal capacitation, decreased motility, abnormal morphology, chemical composition, or antibody presence compromise fertilization. These factors remain unproved.
Male factor infertility is usually identified by a semen analysis in the initial infertility evaluation. Rarely does it present as symptoms in the male. The male partner may have a history of undescended testicles or testicular pain due to a varicocele, but this is usually elicited after the semen analysis is abnormal.
Males with a varicocele will often have a palpable vessel in the scrotum. Otherwise no physical findings are abnormal in most infertile males.
The diagnosis of male factor infertility, as noted begins with a semen analysis. Sonographic evaluation of the scrotum will confirm the presence of a varicocele.
If the infertility is due to a mechanical issue, such as retrograde ejaculation, either pharamacologic or surgical correction of the bladder neck is feasible. In patients with neurological damage from spinal cord or pelvic trauma, multiple sclerosis, or retroperitoneal surgery, rectal electroejaculation or surgical sperm recovery may be utilized. If the male partner is azoospermic due to hypogonadotropic hypogonadism, the patient is treated with gonadotropin therapy. Obstructive azoospermia may be corrected surgically, or sperm recovery techniques such as TESE (testicular sperm extraction)(Figure 11) or MESA (microsurgical epididymal sperm aspiration)(Figure12) may be used. In ICSI (intracytoplasmic sperm injection)(Figure13), an oocyte is mechanically fertilized with a single sperm, a method which ameliorates all but the most severe male factor infertility. Clomiphene citrate is no better than placebo for increasing a low sperm count. \Randomized clinical trials reveal 2 grams of oral L-carnitine therapy was effective in increasing semen quality, particularly motility and especially in groups with lower baseline levels…(43.1)
(For a full discussion on male factor infertility, see Endocrinology of the Male edited by Robert McLachlan, M.D.at http://www.endotext.org/).
Figure 11. Testicular sperm extraction (TESE)TESE: Photo provided by Larry Lipshultz, M.D. Scott Department of Urology Houston, Texas
