Estudio «in vitro» de la influencia de la osmolaridad del plasma seminal en la morfología del espermatozoide

Introduction

Sperm morphology is a parameter closely related to the fertility of the male gamete. Various infertility-causing disorders have been associated with anomalous sperm sub-populations that may be accompanied by an altered osmolality. A pilot study was conducted to determine whether the increase or decrease in in vitro osmolality can alter the original morphology.

Material and methods

The study included 42 randomly selected patients who had been classified as normal according to WHO criteria. The samples were processed by a CASA - SCA 5.4 (Sperm Class Analyzer) (Microptic S.L, Barcelona, Spain). Seminal plasma osmolality was measured using an Advanced Osmometer 2020 3MO.

Results

The in vitro assays carried out on 30 patients showed that an osmolality increase up two times the reference value (880mOsm/kg), caused a progressive loss of sperm viability and a significant increase in macrocephalic sperm heads, with an increase in sperm volume and area. An osmolality decrease (half of the reference value, 228 mOsmol/kg) in a sample of 12 patients had no effect on sperm viability, although the sperm sub-population study showed increased micro-cephalic sperm with lower volume and cephalic area.

Discussion

Sperm morphology is acquired by sperm during the epididymal maturation. It was found that changing in vitro seminal plasma osmolality did not seem to affect it. Only extremely high values of osmolality cause the formation of macrocephalic sperm heads and a progressive loss of viability. These in vitro assays can help us to understand the biochemical seminal plasma effect in the male gamete.