When to Perform Karyotype Analysis in Infertile Men? Validation of the European Association of Urology Guidelines with the Proposal of a New Predictive Model

Known genetic alterations play a major role in perturbing male reproductive health. We sought to retrospectively validate the European Association of Urology (EAU) guidelines for karyotype analysis (KA) in a homogenous cohort of 1168 White European men presenting for primary couple's infertility (noninterracial infertile couples only) and to develop a novel nomogram capable of predicting karyotype alterations. Overall, 742 (63.5%) patients would have deserved KA according to the EAU guidelines. Of those, 48 (6.9% of the assessable patients according to EAU guidelines) displayed any kind of alteration at KA. Conversely, hypothetically relying on the EAU criteria, 12 (20%) out of 60 patients with karyotype abnormalities would not have been candidates for the same genetic assessment. Overall, 694 (62.6%) patients would have been candidates for genetic workup despite having a normal karyotype. As a whole, the EAU guideline sensitivity, specificity, and discrimination were 80%, 37%, and 59%, respectively. We developed a novel nomogram, with a 2% probability cut-off, which allows for a more careful detection of KA alterations.Patient summaryThe application of the European Association of Urology guidelines for karyotype analysis does not ensure an adequate diagnostic process. In this regard, we propose a novel diagnostic tool to improve detection of alterations at karyotype analysis.