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Table 12. Empiric therapy of idiopathic oligoasthenoteratozoospermia syndrome
GnRH = gonadotrophin-releasing hormone; hCG = human chorionic gonadotrophin; hMG = human menopausal gonadotrophin; FSH = follicle-stimulating hormone; IVF = in vitro fertilization; ICSI = intracytoplasmic sperm injection. Gonadotrophin releasing hormone (GnRH) GnRH is effective in hypogonadism. Its application in idiopathic male infertility has been tried with contradictory results [5]. Controlled studies are not available.
The only available randomized controlled study in normogonadotrophic OAT [9] failed to demonstrate any benefit of hCG/hMH therapy.
To date, controlled studies have not detected a significant increase in pregnancy rates due to FSH treatment [5], although one study showed a benefit for reduced testicular volumes [7]. Further controlled trials are necessary to define the value of this therapeutic approach [10].
Administration of supplementary exogenous testosterone has been proposed as a therapy for infertile men with hypogonadism (see above Hypogonadism). The proposed mechanism by which androgens can be used for infertility treatment are the "stimulatory" or "rebound" therapies. A review of the literature [6] determined whether androgen treatment of the male increased pregnancy rates among couples with conception failure attributed to idiopathic oligo- and/or asthenozoospermia. Evaluation of randomized controlled trials using mesterolone or testosterone undecanoate as stimulatory therapy and testosterone-enanthate or testosterone-undecanoate as rebound therapy provided no evidence of effectiveness.
Anti-oestrogens have been commonly used for hormonal treatment for idiopathic oligo- and/or asthenozoospermia. Clomiphene citrate and tamoxifen are the drugs applied in clinical practice. A systematic review of the literature [7] determined whether anti-oestrogen treatment of the male increased pregnancy rates
All four components of the kinin system found in semen have been implicated in the reproductive system. A clear mechanism of action is missing, although multiple suggestions have been made on how increased kinin levels in the genital tract influence spermatogenesis at the testicular level [11]. Uncontrolled studies indicated that kallikrein may be beneficial to men with idiopathic infertility. A systematic review of the literature [8] determined whether treatment of the male with kinin-enhancing drugs increased pregnancy rates among couples with conception failure attributed to idiopathic oligo- and/or asthenozoospermia. Sixteen reports of randomized controlled trials on the therapeutic use of kallikrein or algiotensin-converting enzyme (ACE) inhibitors in subfertile men were analysed, which did not provide proof of effectiveness on pregnancy rates. A modest effect on sperm motility is possible.
Bromocriptine seems to reduce prolactin levels in normogonadotrophic subfertile males, but does not result in an improvement in sperm parameters. Uncontrolled series claiming a beneficial effect are not supported by controlled trials.
Reactive oxygen species (ROS) or free radicals may cause male infertility via peroxidation of phospholipids in the sperm plasma membrane. Antioxidants such as vitamin E or glutathionine interrupt such reactions and scavenge free radicals. One double-blind randomized, placebo-controlled trial [12] was performed to assess the effect of the antioxidant vitamin E. Although the number of pregnancies did not differ significantly, the performance of spermatozoa in the zona binding test was significantly improved after vitamin E administration. In another double-blind randomized trial [13], asthenozoospermic men treated with vitamin E 100 mg/day showed significantly improved sperm motility compared with those who had received placebo, and pregnancy was achieved in 21 % of the treatment group. Re-analysis of these two trials revealed a significant effect on pregnancy, particularly in the second study [5]. Glutathione therapy in a placebo-controlled, double-blind trial demonstrated a significant positive effect on sperm motility [14].
One single-blind, placebo-controlled randomized study [15] evaluated mast cell blockers in the treatment of severe oligozoospermia and revealed a positive effect on pregnancy rates.
One double-blind, placebo-controlled randomized study [16] demonstrated that alpha blocker therapy resulted in significantly improved sperm concentration and motile sperm count, but the cumulative pregnancy rates were not significantly different.
Antisperm antibodies have been associated with infertility in some couples, although the exact pathophysiology of their action remains unclear. They may be found in serum, seminal plasma or bound to spermatozoa, such as IgG and IgA antibodies. Different tests for antisperm antibodies have been published and there are different levels of antibodies at which tests are considered positive. The baseline characteristics of included patients are also different, particularly with regard to duration of infertility, previous genital tract pathology and evaluation of the partner's fertility. All these variables make comparisons among studies difficult. Due to their immunosuppressive effect, glucocorticoids have been used in an attempt to reduce antisperm antibody levels. Three randomized controlled trials and one pseudo-randomized study assessed pregnancy rates after steroid administration to men with antisperm antibodies [17-20]. The situation is difficult due to conflicting evidence from methodologically flawed studies. In a recent meta-analysis of the literature including further trials, no significant influence on pregnancy rates in men presenting with immunological infertility was observed [5].
Drug therapy of idiopathic OAT syndrome is ineffective in many aspects. Controlled studies are necessary in some new fields, e.g. treatment of ROS and immunological infertility. Considering the baseline prognosis for pregnancy, an individual decision is necessary to submit the couple early enough to further reproductive techniques. References 1. O'Donovan A, Vandekerckhove P, Lilford RJ, Hughes E. Treatment of male infertility: is it effective? Review and meta-analyses of published randomized controlled trials. Hum Reprod 1993; 8: 1209-1222. Howard ST. Treatment of male infertility. New Engl J Med 1995; 332: 312-317. Date: 2016-06-12; view: 230
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GnRH therapy is not recommended in OAT.
Human chorionic gonadotrophin (hCG) I Human menopausal gonadotrophin (hMG)
Recombinant follicle-stimulating hormone (FSH)
Androgens are not suggested for therapy in OAT.
A strong treatment effect of anti-oestrogens for oligozoospermia seems to be excluded. A smaller worthwhile effect is possible, which has to be counterbalanced by potential side-effects.
Bromochptine
Although antioxidants may be of benefit in carefully selected groups with OAT syndrome, there is insufficient evidence to recommend their use outside the context of randomized controlled trials.
Treatment with mast cell blockers may be worth further evaluation in OAT.
Alpha blockers are not a recommended treatment for OAT.
Due to lack of proven efficacy, there is consensus that patients with high concentrations of antisperm antibodies in the ejaculate should enter an ICSI protocol.