Fetal factors, umbilical cord factors, placental factors, etc. can lead to the absence of fetal heart. 1. Fetal factors: Fetal gene mutation or chromosomal abnormality can lead to early miscarriage, or even embryonic sterilizations, resulting in the absence of fetal heartbeat. 2. Umbilical cord factors: In the middle and late stages of pregnancy, when the fetus does not have a fetal heartbeat, it should be considered that the umbilical cord is the first factor to be considered, for example, the umbilical cord is twisted or kinked, the umbilical cord is tangled, the umbilical cord thrombosis, and other factors can lead to the absence of the fetal heartbeat. 3. Placental factors: for example, placental abruption can lead to the interruption of blood circulation and nutrition of the fetus, resulting in the absence of fetal heartbeat. 4. Other: Bacterial and viral infections can also cause absence of fetal heartbeat. If the fetus has no fetal heart during pregnancy, it is recommended to go to the hospital immediately.