Sperm Separation and Selection Techniques to Mitigate Sperm DNA Damage

Semen preparation and sperm selection techniques exploit the morphological and physiological characteristics of sperm function, including motility, morphology, density, and maturity, as reflected by their cell-surface charge and the expression of hyaluronan receptors. The various methods employed have a common purpose of mimicing sperm selection within the female reproductive tract and, thereby, increasing the likelihood that oocytes will be fertilised by spermatozoa with intact nuclear DNA and a normal genome. Indeed, the paternal genome is relevant to embryonic genome activation and blastocyst development, and has a fundamental impact upon successful implantation, ongoing pregnancy and live birth. The clinical use of both well-established and some more recently developed techniques is discussed in this comparative clinical review of sperm separation from seminal plasma and selection for insemination.

Embryology outcomes of a device-based sperm separation technique compared to density gradient centrifugation using thawed spermatozoa-a sibling donor oocyte study

OBJECTIVE

To evaluate whether the ZyMōt™ Multi 850 μl sperm separation device (SSD) effectively recovers motile spermatozoa from cryopreserved ejaculates and compare its effect on key embryology outcomes including fertilization, cleavage stage, and total and top-quality blastocyst formation rates to the traditional Density Gradient Centrifugation (DGC) method.

METHODS

In this prospective, single-center, controlled study, we used fresh sibling donor oocytes and non-donor cryopreserved ejaculates. In total, 150 couples participated in this study. At least eight MII donor oocytes were allocated to each couple split into two arms. One arm underwent ICSI with the control DGC-processed sample, and the other arm processed with SSD.

RESULTS

No significant difference on fertilization and cleavage stage embryo rates was observed between the two techniques. We observed a significant increase in the percentage of total (SSD: 74.03 ± 23.47% vs. DGC: 67.86 ± 23.92%; p = 0.016) and top-quality (SSD: 66.38 ± 24.94% vs. DGC: 60.98 ± 24.40%; p = 0.035) blastocysts formed post-SSD processing. Sub-analysis showed that this increase remained significant for the WHO-normal group (n = 118), but not for the WHO-abnormal group (n = 32).

CONCLUSION

The SSD was successfully applied in all 150 cases, providing adequate numbers of spermatozoa to undergo ICSI. Additionally, SSD significantly improved blastocyst development rates; however, this was of limited clinical impact considering the minor improvement on the average number of top-quality blastocysts. It can be hypothesized that this positive contribution may be stronger and clinically significant when a larger number of oocytes is used or in homologous oocyte ICSI cycles, where the repair mechanisms of the oocytes may insufficient for promoting healthy embryo development.

Microfluidics as an emerging paradigm for assisted reproductive technology: A sperm separation perspective

Millions of people are subject to infertility worldwide and one in every six people, regardless of gender, experiences infertility at some period in their life, according to the World Health Organization. Assisted reproductive technologies are defined as a set of procedures that can address the infertility issue among couples, culminating in the alleviation of the condition. However, the costly conventional procedures of assisted reproduction and the inherent vagaries of the processes involved represent a setback for its successful implementation. Microfluidics, an emerging tool for processing low-volume samples, have recently started to play a role in infertility diagnosis and treatment. Given its host of benefits, including manipulating cells at the microscale, repeatability, automation, and superior biocompatibility, microfluidics have been adopted for various procedures in assisted reproduction, ranging from sperm sorting and analysis to more advanced processes such as IVF-on-a-chip. In this review, we try to adopt a more holistic approach and cover different uses of microfluidics for a variety of applications, specifically aimed at sperm separation and analysis. We present various sperm separation microfluidic techniques, categorized as natural and non-natural methods. A few of the recent developments in on-chip fertilization are also discussed.

Causes of Infertility: Diagnosis and Management With Microfluidic Sperm Sorter

This case study refers to a three-and-a-half-year married couple who visited an infertility clinic and are facing infertility for two-and-a-half years. They started in vitro fertilization/assisted reproduction technology (IVF/ART) procedures from December 2021. In 2019, the couple underwent infertility therapy in Wardha, India, including three intra‐uterine insemination (IUI) treatments which failed. The couple was then recommended the intracytoplasmic sperm injection (ICSI) procedure in which the semen sample was separated using a microfluidic sperm sorter for separating good quality sperms. There was no past medical history of both of the partners. Since she was infertile, the desire to have a child was extremely strong. Sadness, helplessness, bewilderment, and frustration are all common feelings associated with infertility. The left fallopian tube delays spillage in females and oligoasthenozoospermia in males; women were detected with secondary infertility and male sperm samples were sorted using a microfluidic sperm sorter and fertilized frozen oocytes for ICSI. As the male partner, in this case, had oligoasthenozoospermia, he was prescribed multivitamins and other medications. After ICSI, the blastocyst formation was good with the use of a microfluidic sperm sorter.