In cryptozoospermia or severe oligozoospermia is sperm freezing useful?

BACKGROUND: Intracytoplasmic Sperm Injection (ICSI) is an Assisted Reproduction Technique (ART) which offers the chance to conceive to patients presenting very low sperm counts (cryptozoospermia/severe oligozoospermia). Sperm freezing before the oocyte pick-up, can prevent from a lack of spermatozoa on the day of the ICSI. It can avoid the cancellation of the ICSI or the use of TESE (Testicular sperm extraction). The objective of this study was to analyse the practice of sperm freezing for these patients in our center over 8 years and the rate of use of these frozen sperms. We also compared the outcome of ICSIs with frozen versus ejaculated sperm. MATERIAL AND METHODS: We performed a retrospective epidemiological study between 2004 and 2011. We recruited all the patients having a sperm count below 1 Million/mL and who were waiting for their first ICSI attempt. RESULTS: 169 patients were recruited: 84 cryopreserved their sperm before the ICSI (secured ICSI) while 85 did not (non-secured ICSI). Both groups were split in cryptozoospermia (<10(3) spermatozoa/ml): 19 and 17 patients respectively, very severe oligozoospermia (10(3)–10(5)/ml): 37 and 13 patients, and severe oligozoospermia (10(5)–10(6)/ml): 28 and 55 patients. The part of secured ICSI significantly increased from 29% during 2004–2007 to 74% during 2008–2011(p = 0.0029) and the frozen sperm was used in 5.9% of the cases. Median age was significantly higher in the non secured ICSI group (33.57 vs 35.52 for men, p = 0.0069 and 30.45 vs 32.26 for women, p = 0.025) but no significant difference was found in the outcome of the ICSI between frozen-thawed sperm and fresh ejaculated sperm. CONCLUSION: Sperm freezing before ICSI for severe oligozoospermic and cryptozoospermic patients significantly increased in our practice but the rate of use remain very low. This encourages to define more accurate criteria leading to sperm freezing. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/2051-4190-24-15) contains supplementary material, which is available to authorized users.