Selective use of percutaneous testis biopsy to optimize IVF-ICSI outcomes: a case series

High Sperm DNA Damage: Does Testicular Sperm Make Sense?

Sperm DNA damage reduces pregnancy rates in couples undergoing in vitro fertilization (IVF). Because it has been shown that testicular sperm have lower DNA damage than ejaculated sperm, it is an attractive idea to consider using testicular sperm for IVF for men with high sperm DNA damage. In fact, there are multiple centers throughout the world now offering sperm retrieval for IVF to manage this condition. However, there is insufficient evidence to conclude that testicular sperm improves pregnancy/live birth rates. Further studies are required before offering sperm retrieval as a standard of care to manage high sperm DNA damage.

DNA fragmentation in epididymal freeze-dried ram spermatozoa impairs embryo development

Sperm freeze-drying is a revolutionary technique, which has been gaining prominence in recent years. The first related significant result was Wakayama and Yanagimachi's demonstration in 1998 of the birth of healthy mouse offspring by Intracytoplasmic Sperm Injection (ICSI), using epididymal freeze-dried spermatozoa. Mouse, rat, and hamster models were the first small mammals born from lyophilized epididymal spermatozoa, whereas most other studies in this field used ejaculated spermatozoa. In this work, we applied this technique to ram epididymal spermatozoa, checking the correlation between DNA integrity and embryo development following ICSI. To do this, epididymal sperm from four rams was lyophilized in a trehalose, glucose, KCl, HEPES, and Trolox media. To evaluate DNA damage and fragmentation after rehydration, samples were processed for Sperm Chromatin Dispersion test (SCD), Two-Tailed Comet Assay, and were used for ICSI. Ram #2 had a higher rate of spermatozoa with intact DNA compared with rams #1, #3, and #4 (28% vs. 3.8%, 2.8%, and 5%, respectively) and the lowest rate of Single-Strand Breaks (SSBs) (70% vs. 95.9%, 92.6%, and 93% respectively). Ram #3 had a higher level of Double-Strand Breaks (DSBs) compared to Ram #1 (4.6% vs. 0.33%, respectively). Embryo development to the blastocyst stage following ICSI was only reached from rams whose sperm had higher level of intact DNA - Rams #2 and #4 (6%, 5/147 and 6.3%, 4/64, respectively). Definitively, the impact of sperm DNA damage on embryonic development depends on the balance between sperm DNA fragmentation extent, fragmentation type (SSBs or DSBs), and the oocyte's repair capacity.

Intracytoplasmic Sperm Injection Outcomes with Freshly Ejaculated Sperms and Testicular or Epididymal Sperm Extraction in Patients with Idiopathic Cryptozoospermia

Background

Cryptozoospermia (CO) is a situation in which spermatozoa cannot be observed in a fresh semen sample unless an extended centrifugation and microscopic search are performed. CO patients are suggested to use only intracytoplasmic sperm injection (ICSI) as infertility treatment. But still there is debate about the choice of sperm source in cryptozoospermic men candidate for ICSI.

Objectives

This study was conducted to evaluate fertility outcomes in men with idiopathic cryptozoospermia who were treated using ICSI with freshly ejaculated sperm and testis sperm extraction (TESE) or percutaneous epididymal sperm aspiration (PESA).

Methods

In this prospective cohort study carried out in an academic institution, 83 out of 92 couples with cryptozoospermia undergoing their first ICSI cycle were recruited. These patients were randomly allocated to two groups: group one (n = 42) who produced freshly ejaculated sperm and, group two (n = 41) who produced a sample by TESE or PESA. The groups were analyzed and compared in terms of fertilization rate, cleavage rate, embryo quality, implantation rate, and clinical pregnancy rate.

Results

There was a significant difference in fertilization rate, embryo quality, implantation rate, and pregnancy rates between the group of surgically extracted sperm and those of naturally ejaculated sperm using conventional ICSI (P < 0.05).

Conclusions

Sperm quality extracted by percutaneous PESA and TESE procedures increases fertility outcomes compared to naturally ejaculated sperm in men with idiopathic CO. More specifically, embryo quality, which is most relevant to fertility outcome, improved when surgically extracted sperm was used for ICSI.