Sperm freezing to address the risk of azoospermia on the day of ICSI

Abstract

Study question: In which cases is freezing of ejaculated sperm indicated before ICSI?

Summary answer: Sperm freezing should be performed only when out of two analyses at least one total sperm count in the ejaculate is lower than 10(6).

What is known already: Due to variations in individual sperm parameters, in cases of severe oligozoospermia there is a risk of absence of spermatozoa on the day of ICSI, leading to cancellation of the attempt. Sperm freezing can avoid this problem but little is known of the parameters governing the decision to freeze sperm or not.

Study design, size, duration: This retrospective study included 247 men who underwent sperm cryopreservation to prevent the risk of azoospermia on the day of ICSI, from 2000 to 2012.

Participants/materials, setting, methods: Receiver operating characteristic curve analysis was used to define the threshold value. The lowest total sperm count per ejaculate was studied as a predictive factor for the use of frozen sperm in a total of 593 ICSI attempts. Moreover, 2003 patients who had at least 4 semen analyses for andrological diagnosis have been studied to evaluate the reproducibility of sperm count. To evaluate the psychological impact of sperm freezing, a questionnaire was administered to 84 men who attended for sperm cryopreservation between June and December 2014. The cost of sperm freezing was analysed according to the French prices.

Main results and the role of chance: When at least one total sperm count was <10(5) the risk of azoospermia in at least one ICSI attempt was 52% (34/66) versus 3% (5/181) when all counts were ≥10(5) (P < 0.0001). However, the study of the reproducibility of pre-ICSI semen analyses has shown wide variations among ejaculates, and therefore sperm freezing is recommended when one analysis from at least two, showed a sperm count <10(6). Such a policy could allow a saving of about €70 000 by avoiding unnecessary sperm freezings. The psychological impact of sperm freezing was good since >70% of men had positive feelings about this technique.

Limitations, reasons for caution: This was a fairly short-term study and preservation of future fertility was not assessed. It appeared impossible to find a threshold that would predict the risk of azoospermia with 100% accuracy. Therefore there is still a risk of absence of spermatozoa on the day of ICSI despite a good negative predictive value when no total sperm count was lower than 10(5).

Wider implications of the findings: These data suggest that sperm freezing should be proposed when total sperm count is lower than 10(6) to avoid cancellation of the ICSI attempt due to azoospermia.

Keywords: ICSI; azoospermia; male factor infertility; sperm count; sperm freezing.