Optimal management of extreme oligozoospermia by an appropriate cryopreservation programme

Severe oligozoospermia is characterized by sperm count fluctuations that may result in insufficient quantities of motile sperm for ICSI on the day of oocyte retrieval, thus necessitating testicular biopsy. To avoid this, we proposed that patients, with transient azoospermia or repeatedly low sperm counts, make a safety pool of frozen spermatozoa before ICSI attempts.

Seventy cryptozoospermic (<10(3) spermatozoa/ml) and 46 oligozoospermic patients (10(3)-10(5)/ml) were included. Although all oligozoospermic patients succeeded in sperm banking, only 44 of 70 cryptozoospermic patients were successful. Others underwent testicular extraction of spermatozoa. The ICSI results for frozen sperm from cryptozoospermic patients were compared with those obtained with fresh sperm from a group of normal patients (>10(5) spermatozoa/ml).

In this prospective matched, controlled study, five cryptozoospermic, but no oligozoospermic, patients failed to produce sperm on the ICSI day, and frozen sperm was used instead. Although fertilization and pregnancy rates (per attempt) using fresh (49% and 5/44, respectively) and frozen sperm (54% and one-fifth, respectively) were similar for this cryptozoospermic group, the results for fresh sperm were significantly lower when compared with the control group (66% and 16/43, P < 0.0001, P < 0.001, respectively). In contrast, results for the oligospermic and control groups were similar.

Banking of ejaculated sperm is helpful for cryptozoospermic patients.