Morphometric and kinematic sperm subpopulations in split ejaculates of normozoospermic men

Area of Science:

• Reproductive Biology
• Andrology
• Spermatozoa Analysis

Background:

• Spermatozoa exhibit diverse kinematic and morphometric characteristics.
• Understanding ejaculate fraction variations is crucial for reproductive health assessments.

Purpose of the Study:

• To analyze sperm kinematic and morphometric subpopulations within different ejaculate fractions.
• To identify variations in sperm characteristics across sequential ejaculates in normozoospermic men.

Main Methods:

• Collected ejaculates from eight normozoospermic men in three fractions.
• Utilized computer-assisted sperm analysis (CASA-Mot and CASA-Morph) for kinematic and morphometric evaluation.
• Applied clustering and discriminant analyses to identify sperm subpopulations.

Main Results:

• Identified three kinematic subpopulations (slow, circular, rapid) and three morphometric subpopulations (large-round, elongated, small).
• Demonstrated significant differences in the distribution of both kinematic and morphometric sperm subpopulations across ejaculate fractions (P < 0.001).
• Observed distinct patterns, with slower sperm prevalent in later fractions and elongated sperm in the first fraction.

Conclusions:

• Significant variations in sperm subpopulations exist between ejaculate fractions.
• These variations may have functional implications for male fertility.
• Ejaculate fractionation reveals heterogeneity in sperm characteristics relevant to reproductive potential.