Bad fetal heartbeat may lead to congenital heart disease, preterm miscarriage and fetal death, which need to be analyzed specifically. 1. Congenital heart disease: If the heartbeat of the fetus is not normal, there may be congenital heart disease, thus showing abnormal heart rate. 2. Pre-eclampsia: If the pregnant woman herself has underlying diseases or complications during pregnancy, the fetus may also suffer from poor growth and development, which is manifested by abnormal fetal heart rate and abnormal fluctuation of the fetal heartbeat, etc. At this time, pre-eclampsia may occur, and it is necessary to keep the fetus in labor in time. 3. Fetal death: If the fetus has chromosomal abnormalities and other diseases or is subject to external stimuli, may affect the physical development of the fetus, or even develop into fetal death, the pregnancy need to count the fetal movement, do a good job of prenatal checkups, and find abnormalities in a timely manner. If the fetus has a bad fetal heart, you need to go to the hospital as soon as possible, under the guidance of the doctor to take reasonable methods of intervention to ensure the safety of mothers and children.