human chorionic gonadotropin (hCG)

(noun)

In molecular biology, human chorionic gonadotropin (hCG) is a hormone produced during pregnancy that is made by the developing placenta after conception, and later by the placental component.

Related Terms

Examples of human chorionic gonadotropin (hCG) in the following topics:

  • Early Pregnancy Tests

    • ., human chorionic gonadotropin (hCG).
    • The first of these markers to be discovered, human chorionic gonadotropin (hCG), is produced by the trophoblast cells of the fertilized ovum (blastocyst).
    • While hCG is a reliable marker of pregnancy, it cannot be detected until after implantation.
    • Direct measurement of antigens, such as hCG, was made possible with the invention of the radioimmunoassay in 1959.
    • Most chemical tests for pregnancy look for the presence of the beta subunit of hCG or human chorionic gonadotropin in the blood or urine. hCG can be detected in urine or blood after implantation, which occurs six to 12 days after fertilization.

  • Implantation

    • In humans, implantation of a blastocyst occurs between 6 to 12 days after ovulation.
    • The chorionic villi grow outwards until they come into contact with the maternal blood supply.
    • The creation of chorionic villi is assisted by hydrolytic enzymes that erode the uterine epithelium.
    • The syncytiotrophoblast also produces human chorionic gonadotropin (hCG), a hormone that notifies the mother's body that she is pregnant and prevents menstruation by sustaining the function of the progesterone-producing corpus luteum within the ovary.
    • Human chorionic gonadotropin is the hormone that is detected by pregnancy tests, as it is found in the maternal bloodstream and urine.

  • Cryptorchidism

    • A recent study published in the European medical journal Human Reproduction examined the prevalence of congenital cryptorchidism among offspring whose mothers had taken mild analgesics, primarily over-the-counter pain medications including ibuprofen (e.g.
    • The most commonly used hormone therapy is human chorionic gonadotropin (hCG).
    • A series of hCG injections (10 injections over 5 weeks is common) is given and the status of the testis/testes is reassessed at the end.

  • Hormonal Regulation of the Female Reproductive Cycle

    • This increased level of estrogen stimulates production of gonadotropin-releasing hormone (GnRH), which increases production of LH.
    • Alternatively, the loss of the corpus luteum can be prevented by implantation of an embryo: after implantation, human embryos produce human chorionic gonadotropin (hCG).
    • Human chorionic gonadotropin is structurally similar to LH and can preserve the corpus luteum.
    • Because the hormone is unique to the embryo, most pregnancy tests look for the presence of hCG.

  • Placenta

    • The umbilical cord inserts into the chorionic plate of the placenta.
    • Human chorionic gonadotropin (hCG) is the first placental hormone produced, which can be found in maternal blood and urine as early as the first missed menstrual period (shortly after implantation has occurred) through about the hundredth day of pregnancy.
    • Women's blood serum will be completely negative for hCG by one to two weeks after birth. hCG testing is proof that all placental tissue is delivered. hCG is present only during pregnancy because it is secreted by the placenta, which is present only during pregnancy.
    • hCG also ensures that the corpus luteum continues to secrete progesterone and estrogen.
    • Progesterone is very important during pregnancy because, when its secretion decreases, the endometrial lining will slough off and pregnancy will be lost. hCG suppresses the maternal immunologic response so the placenta is not rejected.

  • Human Gestation

    • Another layer of the blastocyst, the chorion, begins releasing a hormone called human chorionic gonadotropin (hCG) which makes its way to the corpus luteum, keeping it active.
    • Pregnancy tests determine the level of hCG in urine or serum: if the hormone is present, the test is positive.
    • In humans, fertilization occurs soon after the oocyte leaves the ovary.
    • Describe the development of the human fetus from fertilization through the third trimester

  • Ovarian Cycle

    • The follicular phase (or proliferative phase) is the phase of the menstrual cycle in humans and great apes during which follicles in the ovary mature, ending with ovulation.
    • After implantation, human embryos produce human chorionic gonadotropin (hCG), which is structurally similar to LH and can preserve the corpus luteum.
    • Because the hormone is unique to the embryo, most pregnancy tests look for the presence of hCG.

  • Anatomical Changes

    • The presence of human chorionic gonadotropin (hCG) in the blood and urine.
    • Although the fetus begins to move and takes a recognizable human shape during the first trimester, it is not until the second trimester that movement of the fetus, often referred to as quickening, can be felt by the woman.

  • Physiological Changes

    • Women also experience an increase in human chorionic gonadotropin (β-hCG), which is produced by the placenta and maintains progesterone production by the corpus luteum.
    • Human placental lactogen (HPL) is produced by the placenta, stimulating lipolysis and fatty acid metabolism by the woman and conserving blood glucose for use by the fetus.

  • Puberty

    • Hormones include: 1 Follicle-stimulating hormone - FSH. 2 Luteinizing hormone - LH. 3 Progesterone. 4 Estrogen. 5 Hypothalamus. 6 Pituitary gland. 7 Ovary. 8 Pregnancy - hCG (Human chorionic gonadotropin). 9 Testosterone. 10 Testicle. 11 Incentives. 12 Prolactin - PRL.