Dados do Trabalho

Title

The impacts of human papillomavirus on sperm quality and embrionary implantation rates: a narrative review.

Objective

This review aims to study the influence of human papillomavirus (HPV) in human fertility, especially on sperm quality and the possible risks it can cause to the embryo implantation.

Methods

The present study is a narrative review of the literature searching the ScienceDirect and PubMed databases for the descriptors MeSH: "human papillomavirus", "infertile men", "assisted reproductive technologies" and "sperm motility".

Results

A total of 101 articles were found, removing duplicates and unavailable articles, by the eligibility criteria 9 studies remained for analyses. According to the findings for this study, human papillomavirus (HPV) is one of the most common sexually transmitted infections (STIs) in the world, affecting a large portion of sexually active people at some point of their lives, especially in their young adulthood. HPV is a double DNA strand virus, responsible for causing lesions on the oral and genital mucosa and on the skin. This sexually transmitted disease is also associated to both cancer and male and female infertility. In vitro studies show that sperm quality damage and higher spontaneous abortion rates are related to human papillomavirus infection. In situ hybridization (ISH) studies revealed that the virus DNA is allocated in the head and in the intermediate piece of the spermatozoids, that conducts the virus to the oocyte during fertilization, leading to a possible expression in the developing blastocyst. The presence of the virus was shown to increase apoptosis of the trophoblast cells and therefore reduce the embryo implantation rates, raising the risks of spontaneous abortions. Besides that, there has been a correlation between the HPV infection and the decrease of sperm quality, once the HPV-positive samples presented motility and spermatic concentration significantly reduced when compared to HPV-negative samples. The levels of superoxide dismutase (SOD), an enzyme related to the elimination of reactive oxygen species (ROS) in the seminal plasma were also analyzed and shown to be higher in HPV-positive patients.

Conclusion

The analyzed articles, therefore, provide evidence that the human papillomavirus is related to reduced natural and assisted pregnancy rates and increased miscarriage rates, especially when the virus is found in the male sperm cells. In light of this insight, it is important to perform HPV testing in every couple undergoing infertility treatments, once the possibility of delaying IVF procedures until the viral infection is no longer detected could be taken into consideration in order to increase the pregnancy odds.

Keywords

Human papillomavirus; infertile men; assisted reproductive technologies; sperm motility.