human chorionic gonadotrophin (hCG) (hew-măn kor-i-on-ik) n. a hormone, similar to the pituitary gonadotrophins, that is produced by the placenta during pregnancy and maintains secretion of progesterone by the corpus luteum. Large amounts of hCG are excreted in the urine, and this is used as the basis for most pregnancy tests. Serum hCG monitoring is used for detecting ectopic pregnancies; the hormone is also a marker in prenatal screening tests and for certain malignant tumours. A preparation of hCG is used to treat ovulation disorders and to induce superovulation for in vitro fertilization.

human chorionic gonadotrophin (hCG) See gonadotrophin.