{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Human chorionic gonadotropin (hCG) is a peptide hormone produced in pregnancy, made by the embryo soon after conception and later by the syncytiotrophoblast. Its role is to prevent the disintegration of the corpus luteum of the ovary and thereby maintain progesterone production that is critical for a pregnancy in humans. hCG may have additional functions; for instance, it is thought to affect the immune tolerance of the pregnancy. Early pregnancy testing generally is based on the detection or measurement of hCG."}]}]}