ICSI using testicular spermatozoa after failure of ICSI with ejaculated spermatozoa could be a good choice: A propensity score‐matched cohort study
Authors: Benchaib Mehdi , Labrune Elsa , Giscard d'Estaing Sandrine , Jovet Cynthia , Soignon Gaëlle , Jaeger Pauline , Salle Bruno 
Published: December 2023

Background

Ejaculated spermatozoa are considered to possess a higher fertilisation potential than testicular spermatozoa. In selected cases, the use of testicular spermatozoa from non‐azoospermic infertile men resulted in a higher implantation and pregnancy rate than the use of ejaculated spermatozoa.

Objective

The primary objective was to compare the live birth rate and cumulative live birth rate between couples with failed intracytoplasmic sperm injection procedure using ejaculated spermatozoa who subsequently had an intracytoplasmic sperm injection cycle with testicular spermatozoa and those who subsequently had an intracytoplasmic sperm injection cycle with ejaculated spermatozoa. The secondary objective was to determine the indications for the use of testicular spermatozoa after intracytoplasmic sperm injection failure with ejaculated spermatozoa.

Materials and methods

A retrospective study of matched couples using propensity score matching analysis was performed. After an intracytoplasmic sperm injection failure (cycle_1), intracytoplasmic sperm injection with either ejaculated spermatozoa (ejaculated sperm group), or testicular spermatozoa (testicular sperm group), was performed (cycle_2). The matching was on intracytoplasmic sperm injection performed in cycle_1 according to spermatozoa used (testicular or ejaculated) in cycle_2. Logistic regression was used to evaluate the influence of sperm origin on cumulative live birth rate. Univariate analysis on parameters of cycle_1 was used to identify the prognostic factors to propose an intracytoplasmic sperm injection with testicular spermatozoa in case of cycle_1 failure. The study outcomes were live birth rate and cumulative live birth rate.

Results

Among the 6034 couples available, 63 were selected to constitute the testicular sperm group and 63 were selected by propensity score matching to constitute the ejaculated sperm group. After matching, the DNA fragmentation index was higher in the testicular sperm group (13.43% ± 9.65% vs. 8.93% ± 4.47%, p = 0.013); no significant difference was observed for the fertilisation rate, the number of obtained embryos, blastulation rate and frozen embryo rate. In cycle_2, the live birth rate was higher in the testicular group (22.2% vs. 0.0%, p < 0.001), as was the cumulative live birth rate (25.4% vs. 6.3%, p = 0.065). The prognostic factors identified for the proposal of intracytoplasmic sperm injection procedure with testicular spermatozoa after intracytoplasmic sperm injection failure with ejaculated spermatozoa were: teratozoospermia, cryptozoospermia and high DNA fragmentation index.

Discussion

According to the present study and current knowledge, the use of testicular spermatozoa after failed intracytoplasmic sperm injection procedure in non‐azoospermic men could be proposed instead of sperm donation in case of high sperm DNA fragmentation index, cryptozoospermia and teratozoospermia. A good oocyte response to ovarian stimulation during the previous assisted reproductive technology attempt will increase the chance of success. Although the main limitation of the current study is its retrospective nature, the use of the propensity score matching to perform causal inference study increases its reliability.

Conclusion

The present study supports that the use of testicular spermatozoa outside the classical indication of azoospermia is a good option when the indication is well established. However, before proposing a testicular biopsy, an improvement in sperm characteristics should be considered by treating the causes of sperm alteration.