The clinical manifestations of threatened abortion are slight and occasional bleeding from vagina after pregnancy, or dripping vaginal bleeding, or aching sensation in the loins and abdominal pain as well as prolapsing sensation and distension in the lower abdomen. Abortion is due to either the maternal body or the fetus itself. Abortion is caused either by deficiency of essence in both the wife and husband failing to keep the fetus though able to conceive it; or by weakness of the body and insufficiency of kidney qi; or by intemperance of sexual life and consumption of kidney essence; or by asthenia of both qi and blood; or by pathogenic heat disturbing the fetus; or by other diseases after pregnancy. Besides, falling, sprain, contusion, operation and certain drugs may also lead to abortion.