Low sperm motility may cause fetal arrest. Low sperm motility indicates that the quality of sperm is too poor, which may lead to fetal arrest and so on. Fetal arrest refers to the cessation of early fetal development, most of which occurs within 12 weeks of gestation, and is related to the embryo, the environment, the mother, the father and other factors. The patients manifest the disappearance of early pregnancy reaction and the appearance of a small amount of vaginal bleeding, and there are also some patients who do not have any clinical manifestations, and are only detected in ultrasound examination. Generally speaking, as long as the combination of sperm and egg turns into a fertilized egg, and at the same time, it is successfully deposited in the uterus, the cause of fetal arrest has little to do with male sperm vitality. However, low sperm motility, poor sperm quality and poor embryo development in men may cause fetal arrest. Low sperm vitality may cause fetal arrest, women who have fetal arrest need to go to the hospital in time for relevant examination and treatment.