6 weeks pregnant with fetal heart buds, 8 weeks suddenly no longer may be the embryonic arrest, usually and embryonic abnormalities, maternal factors, environmental factors and other reasons. 1. maternal factors: if the pregnant woman herself suffers from high blood pressure, chronic liver and kidney diseases, and serious infections during pregnancy, it is easy to affect the growth and development of the fetus. 2. Embryonic abnormalities: the disappearance of fetal heartbeat and fetal buds is mostly considered to be embryonic sterilizations, mostly due to the abnormalities of the embryos themselves, due to the elimination of superiority and inferiority. 3. Environmental factors: If during pregnancy long-term exposure to the environment containing a variety of chemicals, such as arsenic, lead, formaldehyde, etc., as well as radioactive rays, high temperatures, etc. may also lead to embryonic sterilizations. If there is an abnormality in the examination, then it is recommended to consult a doctor in time to deal with the symptoms.