AUTHOR=Pook Celina J. , Cocca Alessandra , Grandone Anna , Al-Hussini Mohamed , Lam Wayne TITLE=The Evidence for Fertility Preservation in Pediatric Klinefelter Syndrome JOURNAL=Frontiers in Reproductive Health VOLUME=Volume 3 - 2021 YEAR=2021 URL=https://www.frontiersin.org/journals/reproductive-health/articles/10.3389/frph.2021.629179 DOI=10.3389/frph.2021.629179 ISSN=2673-3153 ABSTRACT=Klinefelter syndrome (KS) is a common cause of non-obstructive azoospermia (NOA). Advances in fertility preservation (FP) techniques, such as the use of microdissection testicular sperm extraction (micro-TESE), have improved sperm retrieval rates (SRR) to 40-50% in this population. Age has been suggested to have an impact on FP, postulating that sperm production may deteriorate over time due to germ cell loss. As such, sperm retrieval for KS patients at a younger age has been proposed to further improve SRR. However, whether such practice pragmatically improve SRR is yet to be determined, and controversy remains with concerns over trauma caused by FP procedures on further impairment of testicular function. There has also been a debate on the ethics of performing FP procedures in the paediatric population. Optimising fertility preservation for KS patients invariably require a holistic multidisciplinary approach. This review aimed to evaluate the latest evidence in performing FP in paediatric KS patients, and discuss the controversy surrounding such practice. Hormonal changes in KS patients during childhood and the use of hormonal manipulation to optimise SSR in this population has also been reviewed.