Surgeons in Japan have achieved a groundbreaking milestone by transplanting kidney tissue from one rat fetus to another while still in the mother’s womb. Led by Takashi Yokoo, the team at Jikei University School of Medicine in Tokyo aims to eventually transplant fetal pig kidneys into human fetuses with impaired kidney development. This pioneering surgery marks the first instance of organ and tissue transplants in utero, distinguishing it from previous injections of cells and amniotic fluid into fetuses. This approach holds promise for allowing organs to develop alongside the fetus, potentially reducing the risk of rejection and ensuring functionality at birth. The accomplishment has been lauded by experts like Glenn Gardener, a fetal surgeon at Mater Mothers’ Hospital in Brisbane, Australia.