High HCG does not necessarily pose a risk to the fetus, and often needs to be analyzed according to the circumstances of its increase. High HCG levels in early pregnancy may be caused by twins or multiple births, deviation in pregnancy week estimation, etc., which usually poses no danger to the fetus; however, if high HCG levels occur in the middle of pregnancy, further non-invasive DNA test or amniocentesis is usually needed to rule out fetal abnormalities. If HCG is abnormally high, even reaching hundreds of thousands of levels, and accompanied by recurrent abdominal pain, vaginal bleeding and other symptoms after ruling out multiple births and wrong estimation of pregnancy, the possibility of hyperemesis gravidarum should be considered, and ultrasound should be used as soon as possible to assist in the diagnosis. If HCG is high during pregnancy, you should consult a doctor as soon as possible, and the doctor should formulate an individualized diagnosis and treatment plan according to the specific situation, so as to avoid adverse consequences.