There are many reasons for the absence of fetal heartbeat, which may be due to poor sperm development, poor egg development or the failure of the fertilized egg to develop properly during the process of fertilization. During the preparation period, men or women may not be able to produce a fetal heart after conception or during the development of the fertilized egg due to bad mood, improper diet, exposure to radiation, or drug stimulation, or the fertilized egg may not be able to differentiate and grow normally after implantation, resulting in the absence of a fetal heart. In addition, there are various endocrine, immune and chromosomal factors that need to be examined in detail at the hospital.