Related Experiment Video
Updated: Oct 24, 2026
Handling and Treatment of Male European Eels (Anguilla anguilla) for Hormonal Maturation and Sperm Cryopreservation
Published on: January 28, 2018
Outcomes with intracytoplasmic sperm injection using fresh vs. frozen elongated spermatids from microsurgical
Jason E Elliott1,2,3, Christopher Labos4, Jim S Meriano5
1Mount Sinai Fertility (MSF), Sinai Health System, Toronto, Ontario, Canada.
Objective:
To evaluate the reproductive outcomes of intracytoplasmic sperm injection (ICSI) using fresh and frozen-thawed elongated spermatids obtained from microsurgical testicular sperm extraction (mTESE) from men with nonobstructive azoospermia.
Design:
Retrospective cohort study.
Subjects:
A total of 256 infertile men underwent one or more mTESE procedures between 2004 and 2017, with the intention of attempting to conceive via ICSI with their female partners.
Exposure:
Intracytoplasmic sperm injection was performed using fresh or frozen-thawed elongated spermatids.
Main Outcome Measures:
Sperm retrieval rate, fertilization rate, blastulation rate, embryo transfer rate, positive β-human chorionic gonadotropin level, clinical pregnancy rate, live birth rate, miscarriage rate.
Results:
A total of 256 men with nonobstructive azoospermia underwent 292 mTESE procedures. Of these, 90 men underwent 99 mTESE procedures in which only elongated spermatids were retrieved, and ICSI was performed later. One hundred-thirty eight ICSI cycles were performed using fresh or frozen elongated spermatids. Overall, fertilization and blastulation rates were 35.3% and 19.3%, respectively. Clinical pregnancy and live birth rates were 4.3% and 2.9%, respectively. There were no differences between live birth outcomes with fresh and frozen elongated spermatids. This relationship persisted after adjusting for male age at the time of mTESE, female age at the time of ICSI, and number of oocytes inseminated (fresh vs. frozen-thawed, odds ratio = 0.40 [0.03-5.33]).
Conclusion:
A nonsignificant difference in reproductive outcomes between fresh and frozen-thawed elongated spermatids can facilitate scheduling of the mTESE procedure before or concurrently with ovarian stimulation cycles without compromising patient outcomes. However, the overall very poor reproductive outcomes with elongated spermatids suggest that very thorough counseling of patients utilizing spermatids should be mandatory, and use of donor sperm should be strongly considered to improve chances of a live birth.
