Acephalic Spermatozoa Syndrome

In 1981, Perotti et al. reported an ultrastructural analysis on the semen sample of an infertile man which showed headless spermatozoa and normal progressive motility (Perotti and Gioria 1981). Most tails had normal structures with proximal centriole at anterior end covered by continuous plasma membrane (Perotti et al. 1981). Acephalic spermatozoa syndrome is a rare but severe type of monomorphic teratozoospermia (which is defined as the presence of a specific defect in almost all spermatozoa). The majority of abnormally shaped spermatozoa include headless tails. Also, a very few percentages of intact spermatozoa with abnormal head-tail junction, and tailless heads can be present in the ejaculate (Zhu et al. 2016). This structural defect can lead to male infertility; however, successful pregnancy is possible by intracytoplasmic sperm injection (Fang et al. 2018).