Efficacy of the Oestrogen Antagonist Tamoxifen on Sperm Parameters in Patients with Idiopathic Oligoathenoteratozoospermia.

Background: The oestrogen antagonist tamoxifen has been suggested as an empiric treatment option for treating idiopathic oligoathenoteratozoospermia (iOAT).

Objectives: To analyse the use of tamoxifen in iOAT.

Method: Fifty-seven men receiving tamoxifen for iOAT were recruited from 2016 to 2017 in a retrospective, single-centre setting. Hormone and semen analysis was performed before and after 3 months of treatment.

Results: After a 3-month treatment, serum levels of testosterone (3.4 ng/mL [2.7-4.8] vs. 5.3 [3.1-7.1]; p = 0.026), follicle stimulating hormone (FSH; 7.6 [5.9-11.5] vs. 15.9 mIU/mL [8.4-19.9]; p = 0.003) and luteinizing hormone (4.5 [3.3-6.6] vs. 7.6 mIU/mL [4.8-10.7]; p = 0.007) significantly increased. At a cut-off of >8.8 mIU/mL, serum levels of FSH were predictive for an improved sperm motility (OR 0.229 [95% CI 0.068-0.773]; p  = 0.018) and serum levels of inhibin B were predictive for an improved total sperm count at a cut-off of <82 ng/L (OR 18.0 [95% CI 1.267-255.744]; p = 0.033). During an 11 month-follow-up, patients receiving tamoxifen showed a clinical pregnancy rate of 42%, leading to a live birth rate of 56% of all pregnant women. Twenty-three per cent of all patients reported non-serious adverse events.

Conclusions: Tamoxifen is effective in improving the total sperm count as well as motility and can thus be safely used as empiric medical therapy in iOAT.