Response to commentary on manuscript: “The impact of fresh versus cryopreserved testicular sperm on intracytoplasmic sperm injection (ICSI) pregnancy outcomes in men with azoospermia due to spermatogenic dysfunction: a meta-analysis”

9 12 2013

To the Editor:

We appreciate the insightful comments of Dr. Kim (1). As he correctly states, the use of fresh versus cryopreserved sperm has been controversial. While the use of frozen sperm from men with obstructive azoospermia appears to yield equivalent outcomes to fresh sperm, the application to men with nonobstructive azoospermia (NOA) is less certain (2). However, if proven equivalent, Dr. Kim correctly emphasizes the significant logistical and economic burdens that could be improved for couples. Additionally, we agree with his assessment on the importance of methodology. We as male reproductive specialists do not have a standardized, evidence-based protocol for the cryopreservation of sperm. As such, we believe that there should be some caution in mentioning an established detrimental effect of cryopreservation. The analyses that produced such findings suffer the same methodological dependence that is inherent within essentially any cryopreservation data to date (3). Moreover, as data from men with obstructive azoospermia suggest equivalent outcomes, it appears that cryopreservation does not irreparably impact sperm function (2). Read the rest of this entry »