Seminal leukocytes are Good Samaritans for spermatozoa

Area of Science:

• Reproductive Medicine
• Andrology
• Infertility Research

Background:

• Leukocytospermia, the presence of leukocytes in semen, is often considered a marker of inflammation or infection.
• Its precise impact on the success rates of assisted reproductive technology (ART) remains a subject of investigation.
• Understanding the role of seminal leukocytes is crucial for optimizing fertility treatments.

Purpose of the Study:

• To evaluate the association between leukocytospermia and outcomes in assisted reproductive technology (ART).
• To determine if the concentration of leukocytes in semen affects fertilization, pregnancy, and infant development.
• To differentiate the effects of moderate versus high levels of leukocytospermia.

Main Methods:

• Retrospective analysis of 3,508 ART procedures (IVF and ICSI) over 7 years.
• Semen samples were analyzed for leukocyte presence using the peroxidase technique.
• Patients were categorized into three groups based on leukocyte concentration: absent, moderate (<10^6/mL), and high (≥10^6/mL).

Main Results:

• Surprisingly, moderate leukocytospermia was associated with significantly improved fertilization rates, cleavage rates, and clinical pregnancy rates.
• No significant differences in fertilization or clinical pregnancy rates were observed between patients with high leukocytospermia and those without leukocytes.
• High levels of seminal leukocytes correlated with increased rates of early pregnancy loss (40.5%) and ectopic pregnancies.

Conclusions:

• Moderate leukocytospermia (<10^6/mL) may be a physiologic condition enhancing sperm fertilization and ART outcomes.
• High concentrations of leukocytes do not impair fertilization or clinical pregnancy rates but negatively impact pregnancy viability.
• The findings suggest a nuanced role for seminal leukocytes in male fertility and ART success.