Lack of effect of a single i.v. dose of oxytocin on sperm output in severely oligozoospermic men.

BACKGROUND ICSI into the oocyte is the only treatment currently available for most male patients with severe oligozoospermia who wish to father children. In order to perform ICSI, motile sperm need to be recovered from the ejaculate and, if no sperm or not enough motile sperm are recovered on the day of ICSI, testicular sperm extraction (TESE) must be performed. Oxytocin stimulates epididymal contractility and may be important for the release of stored sperm. The aim of this randomized single-blind cross-over study was to establish the effects of oxytocin on sperm output in severely oligozoospermic men. METHODS Forty-nine infertile men with sperm concentrations <0.2 x 10(6)/ml were studied on two occasions after 3-4 days of sexual abstinence. They received an i.v. injection of saline or oxytocin 0.75 IU in random order, and commenced masturbation within 5 min. Ejaculate analysis was performed according to the WHO 1999 guidelines. RESULTS A single i.v. dose of oxytocin resulted in no change in ejaculate volume (P = 0.4), total sperm count (P = 0.14) or sperm motility (P = 0.9). There was no significant correlation between the change in total sperm count and FSH levels (r = -0.32, P = 0.2), or the change in total sperm count and estradiol levels (r = -0.02, P = 0.9). Similar results were found in a subgroup of men with total sperm counts of <100. CONCLUSIONS Our data indicate that a single-dose of i.v. oxytocin has no detectable effect on seminal parameters in men with severe oligozoospermia.