Should non-mosaic Klinefelter syndrome men be labelled as infertile in 2009?

BACKGROUND Klinefelter syndrome is a common genetic condition. Affected non-mosaic men are azoospermic and have been labelled as infertile. Despite reports that these men can have children using assisted reproduction techniques, it is not common practice in the UK to offer sperm retrieval to these men.
METHODS Medline and EMBASE (1980–2009) were searched independently by two authors and all studies involving surgical sperm retrieval in non-mosaic Klinefelter syndrome were included. The primary outcome was success of surgical sperm retrieval and the secondary outcome was live birth rate.
RESULTS The overall success rate for sperm retrieval was 44%, with a higher rate of success using micro-dissection testicular sperm aspiration (micro-TESE) (55%). This, along with ICSI, has led to the birth of 101 children. However, there are no known predictors for successful sperm retrieval. Although there are concerns about genetic risk to the offspring of non-mosaic Klinefelter patients, this risk has not been found to be greater than that of patients with non-obstructive azoospermia with normal karyotype.
CONCLUSIONS It is possible for a man with non-mosaic Klinefelter to father a child. However, before these techniques are offered, some ethical issues need to be explored.