human chorionic gonadotropin

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A hormone produced by the placenta that maintains the corpus luteum during pregnancy.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A peptide hormone, produced during pregnancy, that prevents the breakdown of the corpus luteum and maintains progesterone production.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun hormone produced early in pregnancy by the placenta; detection in the urine and serum is the basis for one kind of pregnancy test