Sperm motility in asthenozoospermic semen samples can be improved by incubation in a continuous single culture medium (CSCM®).

ABSTRACT

Standard protocols for clinical in vitro fertilization (IVF) laboratories recommend incubating semen at 37°C in 5% CO2 without strictly specifying which medium should be used or for how long. This study aimed to test the most common different incubation media used in Latin American andrology and micromanipulation laboratories and verify which, if any, is the most appropriate medium to improve asthenozoospermic semen samples' motility in the infertile male population. Ejaculates (136) collected from asthenozoospermic men were divided into two cohorts with similar characteristics (cohort 1; n = 28 and cohort 2; n = 108). Cohort 1 was used to evaluate the optimal incubation time with regard to unprepared asthenozoospermic sample sperm motility. After defining an optimal incubation period of 2 h, cohort 2 was used to evaluate which of the four media commonly used in IVF clinics (continuous single culture medium = CSCM®; SpermRinse medium = SR®; in vitro fertilization medium = G-IVF® and human tubal fluid medium = HTF®) was preferred for semen samples from asthenozoospermic patients. Overall, it was determined that a 2-h incubation in CSCM® medium led to the highest asthenozoospermic sperm motility. Thus, this simple, cost-effective, easily reproducible protocol could prove extremely useful for andrology laboratories working with IVF clinics dealing with asthenozoospermic semen specimens. This is particularly relevant since the incidence of the latter is on the rise as semen quality decreases around the globe.Abbreviations ANOVA Analysis of variance; ARTs Assisted reproductive techniques; BWW Biggers, Whitten, and Whittingham; CO2 Carbon dioxide; CPM counted per minute; CSCM Continuous Single Culture Medium; DAB 3.3'- diaminobenzidine; DFI DNA Fragmentation Index; DMSO Dimethyl sulfoxide; G-IVF In Vitro Fertilization Medium; GSH Glutathione; GPx glutathione peroxidase; HDS High DNA Stainability; HSA Human Serum Albumin; HTF Human Tubal Fluid; HYP Hyperactivity; ICSI Intracytoplasmic sperm injection; IUI Intrauterine insemination; IVF in vitro fertilization; LIN Linearity; ROS Reactive Oxygen Species-level; SC Sperm concentration; SCA Sperm Computer Analysis; SCSA Sperm Chromatin Structural Assay; SR SpermRinse medium; SSS Synthetic Serum Substitute; STR Straightness; SOD superoxide dismutase; TNE Tris-Borate-EDTA; TSC Total sperm count; VAP Mean velocity; VCL Curvilinear velocity; VSL Linear velocity; WHO World Health Organization; WOB Wobble; spz spermatozoa; AO antioxidant.