P–028 Single centre retrospective analysis of endocrine stimulation therapy prior to microsurgical testicular sperm retrieval (mTESE) in men with hypogonadism and non-obstructive azoospermia (NOA)
Authors: Chiriaco G , Naylor K , Talaulikar V , Williamson E , Conway G , Ralph D , Sangster P 
Published: August 2021

Abstract

Study question
What is the role of endocrine stimulation therapy prior to mTESE in men with hypogonadism and non obstructive azoospermia (NOA)?

Summary answer
In hypogonadal men there is a positive correlation between change of serum Testosterone (ΔT) before and after stimulation, and a successful mTESE.

What is known already
NOA is the most common cause of azoospermia and it is often associated with hypogonadism and testicular failure. It is common practice for endocrine stimulation therapies such as gonadotropines or selective estrogens receptor modulators to be used prior mTESE; however there is currently paucity of data regarding their efficacy.

Study design, size, duration
Retrospective analysis on infertile men with hypogonadism (defined as T &lt; 12nmol/L) and NOA who underwent mTESE with or without prior endocrine stimulation therapy (clomiphene or human chorionic gonadotropin). Retrospective data from 2015–2020, total number of patient: 71; stimulated group (N:40) vs unstimulated group (N:31).

Participants/materials, setting, methods
Retrospective study on infertile men who underwent mTESE with or without prior endocrine stimulation therapy. Hypogonadism was defined as serum testosterone (T) level &lt;12nm/L. We recorded demographic data, cause of testicular failure, previous testosterone therapy, duration and type of endocrine stimulation, pre-and post-stimulation hormone levels(T, FSH, LH), pre-operative hormone levels, successful sperm retrieval rate (at least 1 vial of viable sperm), average Johnsen score and total number of vials of sperm retrieved.

Main results and the role of chance
One-hundred-sixty-eight men underwent mTESE out of which 59 men received endocrine stimulation therapy for NOA between 2015–2020. Among them, we selected men with hypogonadism defined as serum T &lt; 12nmol/L which comprised 43% of the entire patient cohort. The hypogonadal group included 71 men, 28/71 had Klinefelter syndrome and 40/71 received endocrine stimulation for 13.9±9.2 months.
Testosterone levels significantly increased after endocrine stimulation (6.3±3.3nm/L vs 11.7±7.4nm/L) with mean change in serum testosterone (ΔT) of 5.7 nm/L (–5.5–23.3, N35). In the stimulated group, pre-operative serum T levels were significantly higher (11.7±7.4 vs 7.8±3.0 p:0.007) as compared to unstimulated men but the success rate of mTESE did not differ significantly (16/40–40%) vs 13/31–42%). Men with Klinefelter syndrome demonstrated significant differences with regards to age, lower T levels, higher FSH and LH levels, lower Johnsen score and success rates compared to other causes of NOA. Comparing men who had successful mTESE vs unsuccessful mTESE - higher T and lower FSH and LH seemed to correlate with successful sperm retrieval. Among men who received endocrine stimulation therapy the ΔT before and after stimulation seemed to correlate with successful sperm retrieval (AUC:0.701, SE:0.089, p:0.043). In the stimulated group a ΔT&gt;3.5nm/L showed a significant association with successful mTESE(p:0.041).

Limitations, reasons for caution
Retrospective study limitations.
Wider implications of the findings: Our study shows a significant improvement of serum T following endocrine stimulation therapy. Overall, in hypogonadal men, the hormonal stimulation seems not to be related to a higher success rate of mTESE but our data do suggest a positive correlation between ΔT before and after stimulation, and a successful mTESE.

Trial registration number
Not applicable