Follicle-stimulating hormone bioactivity in idiopathic normogonadotropic oligoasthenozoospermia: double-blind trial with gonadotropin-releasing hormone.

OBJECTIVE

To identify, among patients with idiopathic normogonadotropic oligoasthenozoospermia, those with low bioactive follicle-stimulating hormone (FSH), possibly because of inadequate gonadotropin-releasing hormone (GnRH) pulsatility, whose bioactive FSH and sperm could be improved by GnRH treatment.

DESIGN

Randomized, double-blind, placebo-controlled trial with intranasal (IN) GnRH, followed by open GnRH treatment.

SETTING

Outpatient endocrinology clinic.

PATIENTS

Twenty-eight infertile men with idiopathic normogonadotropic oligoasthenozoospermia.

INTERVENTIONS

Gonadotropin-releasing hormone or placebo was self-administered IN every 2 hours.

MAIN OUTCOME MEASURES

Serum immunoreactive and bioactive FSH and semen analyses.

RESULTS

Ten men showed a low basal FSH bioactive/immunoreactive ratio, which increased in 5 of them under GnRH without parallel sperm modification. Sperm improvements were observed in 10 patients with no parallel evolution of FSH bioactive/immunoreactive ratio. Unpredicted by sperm changes, three pregnancies developed on placebo and 5 on GnRH.

CONCLUSIONS

Low bioactive FSH was not the cause of idiopathic normogonadotropic oligoasthenozoospermia in our patients and could not predict response to GnRH. Pulsatile GnRH did not improve sperm beyond random fluctuations.