Embryonic arrest refers to a condition in early pregnancy where no fetal heartbeat appears in the gestational sac. The diagnostic criteria mainly include the lack of observable primitive heart tube pulsation via ultrasound after two months of pregnancy, at which point embryonic arrest can be confirmed. The definitive diagnosis of embryonic arrest is primarily through ultrasound. The following situations observed during an ultrasound can lead to a diagnosis of embryonic arrest: 1. If the diameter of the gestational sac exceeds three centimeters without a clear fetal heartbeat or embryo visible inside, it can be diagnosed as embryonic arrest. 2. If an embryo is already present and approximately 10 days after the appearance of the embryo, an ultrasound still does not show a fetal heartbeat, this situation can also be determined as embryonic arrest.