Sperm morphology: What implications on the assisted reproductive outcomes?

Area of Science:

• Reproductive Medicine
• Embryology
• Andrology

Background:

• Sperm morphology (SM) is a key indicator of male fertility.
• Conventional intracytoplasmic sperm injection (c-ICSI) is widely used in assisted reproductive technologies.
• The influence of SM on c-ICSI outcomes requires further elucidation, particularly by controlling for female factors.

Purpose of the Study:

• To assess the impact of sperm morphology on laboratory and pregnancy outcomes in conventional intracytoplasmic sperm injection (c-ICSI) cycles.
• To utilize an egg donation model to minimize confounding variables related to the female recipient.

Main Methods:

• Retrospective analysis of oocyte donation cycles from October 2016 to February 2020.
• Categorization of study population into three groups based on normal sperm morphology (SM <4%, 4-6%, >6%).
• Collection and comparison of laboratory parameters (fertilization, cleavage rates) and clinical outcomes (implantation, pregnancy, live birth rates).

Main Results:

• A total of 741 fresh c-ICSI cycles were analyzed.
• Significantly higher 2-pronuclear fertilization rates (2PN FR) were observed in the group with SM >6% compared to SM <4%.
• Implantation rates (IR), clinical pregnancy rates (PR), and live birth rates (LBR) were significantly higher in the group with normal SM >6%.

Conclusions:

• Normal sperm morphology plays a crucial role in achieving successful assisted reproductive outcomes.
• Higher normal sperm morphology is associated with improved laboratory and clinical results in c-ICSI.
• Male factor, including sperm morphology, remains a critical determinant of success in fertility treatments.