Spermatozoal fertilizing capacity in polyzoospermia: a preliminary study

Area of Science:

• Reproductive Biology
• Andrology
• Human Fertility

Background:

• Polyzoospermia, defined as a sperm concentration greater than 250 x 10^6 sperm/ml, is often associated with reduced male fertility.
• The underlying causes of infertility in men with polyzoospermia are not fully understood.

Purpose of the Study:

• To investigate the in vitro fertilizing capacity of spermatozoa in men with polyzoospermia.
• To compare the fertilizing potential of sperm from polyzoospermic men with that of normospermic fertile men.

Main Methods:

• The study utilized the human sperm and zona-free hamster ova penetration bioassay.
• Semen parameters, including sperm motility and morphology, were assessed.
• Fertilizing capacity was evaluated in 12 men with polyzoospermia and 22 normospermic fertile men.

Main Results:

• No significant differences were observed in sperm motility, normal morphology, or in vitro fertilizing capacity between polyzoospermic and normospermic men.
• The sperm of the studied polyzoospermic men demonstrated normal fertilizing capacity in the heterologous sperm-oocyte penetration assay.

Conclusions:

• The findings suggest that polyzoospermia itself, as assessed by sperm penetration assays, is not indicative of impaired spermatozoal fertilizing capacity.
• The literature's reported fertility impairments and higher abortion rates in couples with polyzoospermic partners may stem from other factors, such as chromosomal aberrations or unknown functional defects.