Mitochondrial replacement therapy (MRT), also known as mitochondrial donation, is a technique that aims to prevent the transmission of mitochondrial DNA (mtDNA) disorders from mother to child. This involves replacing defective mitochondria in an egg or embryo with healthy mitochondria from a donor, preventing mitochondrial diseases in offspring. Thus, MRT has been used to create embryos with genetic material from three individuals: the mother, the father, and a mitochondrial donor (so called "three-parent babies"). MRT raises ethical concerns related to genetic modification and the long-term effects on future generations. MRT is particularly beneficial for women with mitochondrial disorders who wish to have genetically related children. The technology is currently regulated differently across countries, with some permitting its use under strict guidelines and others banning it outright. Gene editing and MRT technologies are compared in Table . Intracytoplasmic sperm injection (ICSI) is an ART procedure that involves injecting live sperm directly into the cytoplasm of a mature egg using a micromanipulation tool. The fertilized egg is then cultured and transferred as in IVF It represents a refinement of IVF and is the most common and successful treatment for male infertility caused by sperm issues, such as low sperm count, poor motility, or abnormal morphology, or when previous IVF attempts have failed. Success rates are similar to IVF, but ICSI can significantly improve fertilization rates in cases of male infertility. 107