Embryonic arrest, also known as missed miscarriage, refers to the restriction of growth and development of the gestational sac in early pregnancy due to various factors, with no fetal heartbeat detected on an ultrasound at 9 weeks of pregnancy. When embryonic arrest occurs, a natural miscarriage may happen, but it's also possible that a natural miscarriage won't occur. Once embryonic arrest is confirmed, waiting for a natural miscarriage isn't advisable, as it is unpredictable and sometimes there might be no signs of miscarriage for a long time. Unrestricted waiting in such cases can harm a woman's body. Therefore, once embryonic arrest is diagnosed, hospitalization should be promptly sought, and artificial intervention methods such as surgical or medical abortion should be considered. While there is a possibility that the embryo could be expelled naturally, the likelihood is relatively low.