Increasing the success of assisted reproduction by defining sperm fertility markers and selecting sperm with the best molecular profile

Male factors are responsible for 50% of cases that are considered for fertility problems – one half of them idiopathic. Basic sperm analysis under the WHO premises is the only tool to assess male fertility but its predictive value to measure male capacity to have a newborn is limited. Success rates are far from 100% in assisted reproduction, pointing to the need for new diagnostic and sperm selection tools. To determine which are the most desirable features for a sperm cell to succeed, several molecular markers are being tested. Once described, the possibility arises of designing different methodologies to select the optimum sperm among millions, subsequently reducing the failure chances. The aim of this work is to discuss the relevance of sperm molecular markers available to develop tools that allow the objective and evidence-based selection of sperm with the best molecular and physiological profile to be employed in assisted reproduction technology to enhance newborn achievement likelihood.