HCG is also important after finding out the fetal heart and buds. However, usually the presence of fetal heartbeat and development of fetal buds means that the embryo is well developed and HCG test is not necessary. if the patient has vaginal bleeding and abdominal pain, then blood HCG and progesterone tests are needed to determine the development of the embryo. This is because even if the fetal heart and buds appear, miscarriage and embryonic arrest may still occur. If the test results show a decrease in HCG or progesterone levels, it often indicates a poor prognosis for embryo development. This is why it is important to monitor HCG during pregnancy to effectively promote healthy fetal development throughout the pregnancy. It is especially important to monitor the doubling of HCG in patients with a history of miscarriage or embryonic arrest. Only a good doubling of HCG and the absence of bleeding and abdominal pain can indicate normal embryonic development. In addition, HCG is useful in the diagnosis and monitoring of ectopic pregnancies and gestational trophoblastic diseases, such as ectopic pregnancy and gravida.