부산대학교 도서관

Simple Summary: Couples attending infertility clinics may suffer failed attempts and need consecutive treatments to achieve a healthy newborn, proving that there is room for improvement among the techniques we currently use. Selection of the right sperm—the most physiologically competent one—to be injected inside the egg among all available within the ejaculate is crucial to create good-quality embryos and increase cycle success rates. It is probably the step with the highest number of possibilities to choose from influencing the final outcomes. Apoptotic sperm, those undergoing programmed cell death, do not differ morphologically from healthy ones, their presence has been described as elevated in the ejaculates of infertile men, and they can fertilize the egg in both natural and artificial conception. In the latter, they can be unconsciously chosen by the embryologist and result in a poor-quality embryo that will stop developing or fail to implant. MACS enables the removal of apoptotic sperm from an ejaculate, thus leaving the non-apoptotic available to be microinjected. The existing literature on the topic provides conflicting evidence of variable quality that needs to be scrutinized and interpreted in order to define what is the benefit, if any, of using this technology and if this fits all infertile patients. We aim to provide clinicians and patients with a more accurate interpretation on how, when, and by how much, the use of MACS may impact their reproductive chances under an evidence-based medicine approach. Sperm selection of the most competent sperm is a promising way to enhance reproductive outcomes. Apoptosis is the programmed cell death process to maintain tissue homeostasis, and MACS sperm selection of non-apoptotic cells enables the removal of apoptotic sperm from an ejaculate, thus leaving the non-apoptotic available to be microinjected, but given the associated costs of adding these sperm selection steps to the routine practice, there is a need for a careful examination of the literature available to answer questions such as who can benefit from this MACS, how significant this improvement is, and how robust the evidence and data available supporting this choice are. Thus, the aim of this narrative review was to objectively evaluate the available evidence regarding the potential benefits of the use of MACS. From the literature, there are controversial results since its implementation as an in vitro fertilization add-on, and this may be explained in part by the low quality of the evidence available, wrong designs, or even inadequate statistical analyses. We concluded that the benefits of adding MACS are unclear, and further methodologically sound research on specific populations is much needed before offering it clinically. [ABSTRACT FROM AUTHOR]