Microfluidic sperm sorting improves ICSI outcomes in patients with increased values of Double-Strand Breaks in sperm DNA / La selección espermática mediante un dispositivo microfluídico mejora los resultados de ICSI en pacientes con valores elevados de fragmentación de cadena doble en el ADN espermático

Background: Delays in embryo kinetics, implantation failures in ICSI treatments and recurrent miscarriages have been associated with high values of Double-Strand Breaks (DSB) in sperm DNA. While conventional methods for semen preparation have been shown to be inefficient reducing DSB values, Microfluidic Sperm Sorting (MSS) devices are promising tools to reduce this damage. Objective: To study the clinical utility of an MSS device in ICSI treatments when the male partner presents increased DSB values, as compared to the use of conventional methods based on sperm motility. Methods: This retrospective cohort study included 28 infertile couples undergoing ICSI treatments. Only couples where the male partner presented increased values of DSB were included. DSB values were evaluated in semen samples by the Neutral Comet assay. Couples performed a first ICSI cycle using conventional methods for semen preparation (Density Gradients and Swim-up) and a second ICSI cycle using the ZyMōt™ICSI (formerly named FertileChip®) microfluidic device. Embryology and clinical outcomes were compared between ICSI cycles. Results: Semen parameters and the number of obtained and fertilized oocytes did not show differences between ICSI rounds. Clinical outcomes were statistically better when MSS was used: the biochemical pregnancy rate increased 28.31%; the clinical pregnancy rate increased 35.56% and the number of live births increased 35.29%, as compared to the first ICSI cycle in this group of patients. (AU)

Antecedentes: Valores elevados de fragmentación de cadena doble (DSB) en el ADN de los espermatozoides se han asociado con retrasos en la cinética embrionaria, fallos de implantación en ciclos de ICSI y con abortos de repetición. Actualmente no hay evidencias de que los métodos convencionales para la preparación del semen puedan reducir los niveles de DSB. Por el contrario, los nuevos dispositivos microfluídicos de selección espermática (MSS) han mostrado resultados prometedores en cuanto a la reducción de la fragmentación. Objetivo: Evaluar el uso de un dispositivo MSS en ciclos de ICSI donde el varón presenta niveles elevados de DSB, en comparación con el uso de métodos convencionales basados en la selección por motilidad. Métodos: Este estudio retrospectivo ha incluido a 28 parejas infértiles que han realizado ciclos de ICSI y donde se han detectado valores elevados de DSB en la muestra seminal del varón. Los niveles de DSB se han analizado mediante el test Cometa Neutro. Las parejas realizaron un primer ciclo de ICSI utilizando métodos convencionales para la preparación del semen (gradientes de densidad y Swim-up). Posteriormente, las parejas realizaron un segundo ciclo de ICSI utilizando el dispositivo microfluídico ZyMōt™ICSI (antes FertileChip®). Se han comparado los resultados de embriología y los resultados clínicos entre ambos tratamientos. Resultados: No se han encontrado diferencias entre ambos ciclos de ICSI en cuanto a parámetros seminales y el número de ovocitos obtenidos y fecundados. Los resultados clínicos fueron mejores cuando se usó el dispositivo MSS: se observó un incremento del 28,31% en la tasa de embarazo bioquímico, del 35,56% en la tasa de embarazo clínico y del 35,29% en la tasa de nacidos vivos, en comparación con el uso de métodos convencionales. (AU)

Microfluidic sperm sorting improves ICSI outcomes in patients with increased values of Double-Strand Breaks in sperm DNA.

BACKGROUND: Delays in embryo kinetics, implantation failures in ICSI treatments and recurrent miscarriages have been associated with high values of Double-Strand Breaks (DSB) in sperm DNA. While conventional methods for semen preparation have been shown to be inefficient reducing DSB values, Microfluidic Sperm Sorting (MSS) devices are promising tools to reduce this damage. OBJECTIVE: To study the clinical utility of an MSS device in ICSI treatments when the male partner presents increased DSB values, as compared to the use of conventional methods based on sperm motility. METHODS: This retrospective cohort study included 28 infertile couples undergoing ICSI treatments. Only couples where the male partner presented increased values of DSB were included. DSB values were evaluated in semen samples by the Neutral Comet assay. Couples performed a first ICSI cycle using conventional methods for semen preparation (Density Gradients and Swim-up) and a second ICSI cycle using the ZyMot™ICSI (formerly named FertileChip®) microfluidic device. Embryology and clinical outcomes were compared between ICSI cycles. RESULTS: Semen parameters and the number of obtained and fertilized oocytes did not show differences between ICSI rounds. Clinical outcomes were statistically better when MSS was used: the biochemical pregnancy rate increased 28.31%; the clinical pregnancy rate increased 35.56% and the number of live births increased 35.29%, as compared to the first ICSI cycle in this group of patients. CONCLUSIONS: The ZyMot™ICSI microfluidic device improved the reproductive outcomes in couples where the male partner presented increased DSB values, when compared to the use of conventional semen preparation techniques.

Sperm selection during ICSI treatments reduces single- but not double-strand DNA break values compared to the semen sample.

PURPOSE: To detect a possible bias in sperm DNA fragmentation (SDF) testing when performed on semen samples or on those few spermatozoa selected for Intracytoplasmic Sperm Injection (ICSI) treatments. METHODS: A multimethodological analysis of Single- and Double-Strand DNA Breaks (SSB and DSB, respectively) was performed through the Neutral Comet, the Alkaline Comet, the Sperm Chromatin Dispersion (SCD) and the Terminal deoxynucleotidyl transferase dUTP Nick End Labelling (TUNEL) assays. SDF was evaluated in (i) semen samples from 23 infertile patients (not achieving pregnancy or suffering recurrent miscarriage); (ii) samples after a Swim-up and (iii) spermatozoa microselected for ICSI (ICSI-S). RESULTS: The analysis of 3217 ICSI-S revealed a significant reduction of SSB values compared to the Ejaculate and the Swim-up samples. On the contrary, DSB values were not reduced after any sperm selection method. The No-pregnancy group presented poorer semen parameters and higher SSB values. The Recurrent miscarriage group presented better semen parameters but also higher DSB values. CONCLUSION: The analysis of SDF on semen samples may not be fully representative of those few spermatozoa selected for ICSI. Since oxidative stress impairs sperm motility and causes SSB, selecting a motile sperm may intrinsically imply choosing a sperm not affected by this damage. DSB have an enzymatic origin which does not affect motility, making it difficult to select a sperm without this damage. Therefore, ICSI treatments could be effective in patients presenting high SSB values. Patients presenting high DSB values should expect bad ICSI results if this damage is not reduced through other specific methods.