Infection with the human papillomavirus (HPV) represents one of the most widespread sexually transmitted diseases, affecting both genders. Over 100 types of HPV can cause infections in the skin or mucous membranes and are typically transmitted through skin-to-skin contact, vaginal or anal intercourse, as well as oral sex. Statistics indicate that between 50 and 80 percent of sexually active adults will experience genital HPV infections during their lifetime. These infections tend to be persistent, especially in men. Although most HPV infections are asymptomatic, they can lead to genital warts, dysplasia, cancer, infertility, and may impact the outcomes of in vitro fertilization (IVF). Despite extensive research on HPV-related conditions in women, there has been limited attention given to HPV-related conditions in men.

A systematic review and meta-analysis conducted in 2017, comprising 31 studies, revealed that the prevalence of HPV DNA in semen samples among men in the general population was 11.4%, rising to 20.4% among men with infertility. It remains unclear whether HPV localizes in seminal plasma or in cellular fractions of semen samples (such as sperm, epithelial cells, or leukocytes). Recent evidence has shown that HPV DNA can be found on the surface of sperm by binding to specific glycosaminoglycans (GAGs), such as syndecan-1, along the equatorial region of the sperm head. Additionally, a few in vitro studies have indicated that HPV DNA can be found inside sperm when mixed with the HPV virus. The potential effects of HPV on fertility are not yet fully understood. The presence of HPV infection in sperm has been associated with impaired sperm parameters, mainly sperm motility, and increased sperm DNA fragmentation. Existing evidence suggests a negative effect of HPV DNA in seminal plasma and/or on sperm on the number of live births and ongoing pregnancies, although the level of evidence remains limited. Considering that sperm is utilized in IVF, it is crucial to investigate the presence of HPV in seminal plasma and sperm in these men, as well as any potential consequences on embryo development following IVF.

The primary objective of this study is to assess the prevalence of HPV DNA in seminal plasma and/or on sperm in men undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatments. Furthermore, the study aims to characterize semen parameters in men with HPV-positive (HPV+) and HPV-negative (HPV-) semen samples and analyze the embryological outcomes after IVF/ICSI in men with HPV+ semen samples compared to men with HPV- semen samples.

The secondary objectives include evaluating semen parameters such as volume, sperm concentration, and motility to determine if there are differences between men with HPV+ and HPV- semen samples. Additionally, the study aims to investigate whether the embryological outcome (fertilization rate, number of high-quality embryos) after IVF/ICSI treatment differs between men with HPV+ and HPV- semen samples.

Analyses of HPV DNA in seminal plasma and/or on sperm will be conducted using the method that has demonstrated the highest performance in detecting HPV DNA, based on a previously conducted pilot study. Sperm samples are typically provided at the Fertility Laboratory at the Department of Reproductive Medicine, SU, in conjunction with infertility investigations and IVF/ICSI treatments. Usually, up to 2 mL of ejaculated sperm sample undergo gradient centrifugation, separating motile sperm from seminal plasma, immotile sperm, squamous epithelial cells, leukocytes, and bacteria. A portion of the pellet containing motile sperm is used to analyze sample parameters, primarily concentration and motility. During IVF/ICSI treatments, parts of the sperm sample are utilized for egg fertilization while the remainder is discarded. Following gradient centrifugation, sperm samples are diluted with a preservation liquid (ThinPrep®, 1:2) and stored in a refrigerator for transport to the Clinical Microbiology Department (virological laboratory) at SU (once per week) for polymerase chain reaction (PCR) analysis. ThinPrep® is routinely used to preserve and fix cell samples for HPV analysis in women. In this study, the portion of the sperm sample typically discarded and not used for IVF treatment will be utilized for HPV DNA analysis using PCR. PCR is the method routinely employed at the Clinical Microbiology Department (virological laboratory) at SU for HPV DNA detection in cervical cell samples. Results from these analyses will be correlated with sample parameters and the embryological outcome following completed IVF/ICSI treatment. Once analyzed by PCR and upon the availability of material, the samples will be stored for 5 years at Biobank Väst for potential future analyses of HPV-related biomarkers.