Significance of Positive Semen Culture in Relation to Male Infertility and the Assisted Reproductive Technology Process

Joshua S. Jue, Ranjith Ramasamy


Transl Androl Urol. 2017;6(5):916-922. 

In This Article

Abstract and Introduction


There are currently no WHO guidelines on the indications for semen culture; however, semen cultures are performed in the evaluation of male infertility and the assisted reproductive technology (ART) process. The relevance and significance of positive semen cultures is widely debated in the literature, with no current consensus on the usefulness of this test in relation to male infertility. We review the pathogenic mechanisms of potentially pathogenic bacteria, general bacteria, urethral flora, and skin flora on sperm parameters. We also present, possible routes of semen contamination, measures to reduce contamination, and the clinical significance of culture contamination. First, it is critical to distinguish round cells in semen as leukocytes from immature germ cells. Second, it is critical to distinguish leukocytospermia from infected semen in order to guide management.


Positive semen cultures are common in in vitro fertilization (IVF) clinics, with significant differences in sperm quality and cultured pathogens seen among men. It is unclear whether this is a sign of male infertility or more relevant for the IVF process. Limited data without any unifying sperm abnormalities between studies has kept the indication and significance of semen culture a highly debated topic. To compound the situation, there are currently no guidelines by the World Health Organization (WHO) or American Urological Association (AUA) on the indications of semen culture and the details of treatment.

The current WHO guidelines regarding sterile preparation prior to semen collection are rudimentary and listed in Table 1.[1] Most studies follow these WHO guidelines or add additional sterilization precautions. Although the WHO provides a simplified preparation technique, it does not provide "normal" levels of organisms for semen culture. Inconsistent control groups, definitions of "positive culture," interpretations of multiple pathogen groups, and recordings of "nonpathogenic organisms" among studies has made comparisons and conclusions difficult.

We present the pathogenic mechanisms of several organisms, significance of each organism for impaired semen parameters, possible routes of semen sample contamination, and methods to reduce contamination. We also discuss the association with leukocytospermia and mechanisms of damaging sperm.