Sperm recovery from urine in men with retrograde ejaculation

Abstract Introduction Retrograde ejaculation (RE) consists of the reflux backwards, towards the bladder, of the ejaculate, during the emission phase of ejaculation, causing a total or partial absence of sperm emission, with the consequent diversion of semen into the bladder during the emission phase of ejaculation. Evaluating the ejaculate may not be sufficient for identifying RE in some patients. Hence, the management of infertility may involve the use of invasive methods such as epididymal fluid retrieval or testicular biopsy. Content This paper defines RE and methods for its diagnosis. A description is also provided of the techniques used for the detection of sperm in post-ejaculatory urine (PEU), the preparation and retrieval of sperm from urine and their subsequent use in assisted reproductive techniques. Summary The diagnosis of RE is based on the detection of spermatozoa in PEU in patients with aspermia or oligozoospermia and low or normal seminal volume. Although the presence of sperm in PEU could be sufficient for a diagnosis of RE, there is a lack of consensus regarding the diagnostic criteria for PEU, and the literature available is very limited. A correct diagnosis of RE allows the use of PEU for recovering sperm and its subsequent use in assisted human reproduction techniques, thus avoiding invasive techniques. Outlook A significant number of patients with RE may remain undiagnosed. Therefore, it is essential to conduct an RE study in patients with suspicion, through the analysis of PEU, and to properly interpret the results for accurate diagnosis.