China: Aromatase Inhibitors and Male Infertility

Aromatase inhibitors (AIs) may be effective for the treatment of male infertility, according to a recent study in the journal Andrology. AIs discontinuation for 2-7 days before sperm retrieval may increase the success rate of fertilization for infertile male patients planning assisted reproduction.

For decades, aromatase inhibitors have been utilized for treating male fertility. Still, the safety and efficacy of AIs in the treatment of male infertility remain controversial due to the lack of large-scale randomized controlled studies and basic research. Therefore, there is a need to conduct an evidence-based preliminary evaluation of the existing clinical trials of AIs in the treatment of male infertility.

Considering the above, Jian-guo Liu, Department of Andrology, Shaanxi Provincial Hospital of Traditional Chinese Medicine, Xi'an, Shaanxi, China, and colleagues conducted a systematic review with a meta-analysis of all available studies reporting sperm conventional parameters, gonadotropin and testosterone levels, and/or the pregnancy rate. They performed a comprehensive literature search in the PubMed, Embase, Cochrane, CNKI, VIP, CBM, and Wanfang databases through August 2021 for all studies. A total of 10 studies involving 666 patients were included.

Findings

• Letrozole (LE) or anastrozole (AZ) administration significantly increased sperm concentration, total sperm count, serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T) levels, and the testosterone-to-estradiol ratio (T/E2), but E2 levels were significantly reduced compared with baseline values.
• Compared with the control group, which included selective estrogen receptor modulators (SEMRs) or human chorionic gonadotropin (HCG), LE, or AZ did not have any significant effect on sperm concentration, motility, and morphology, except that AIs had less effect on sperm motility than the control group (weighted mean difference [WMD]: −2.55).

To conclude, "AIs may be an effective treatment for male fertility. For infertile male patients planning assisted reproduction, discontinuation of AIs for 2–7 days prior to sperm retrieval may increase the success rate of fertilization."

"Further studies with larger sample sizes are needed to validate these findings," the researchers wrote.

Reference

Guo B, Li JJ, Ma YL, Zhao YT, Liu JG. Efficacy and safety of letrozole or anastrozole in the treatment of male infertility with low testosterone-estradiol ratio: A meta-analysis and systematic review. Andrology. 2022 Apr 19. doi: 10.1111/andr.13185. Epub ahead of print. PMID: 35438843.