In females, human chorionic gonadotropin (hCG) primarily functions to support early pregnancy by maintaining the corpus luteum.
Here's a more detailed explanation:
-
Maintaining the Corpus Luteum: The primary function of hCG is to maintain the corpus luteum, a temporary endocrine gland in the ovary. After ovulation, the follicle that released the egg transforms into the corpus luteum. The corpus luteum produces progesterone and estrogen, which are crucial for preparing and maintaining the uterine lining (endometrium) for implantation of a fertilized egg. If pregnancy doesn't occur, the corpus luteum degrades, and hormone levels drop, leading to menstruation.
-
Preventing Menstruation: By maintaining the corpus luteum, hCG ensures that progesterone and estrogen levels remain high, preventing the shedding of the uterine lining and thus stopping menstruation. This is essential for sustaining the pregnancy.
-
Supporting Embryonic Development: The progesterone produced by the corpus luteum, under the influence of hCG, creates a suitable environment for the developing embryo. It thickens the uterine lining and provides nutrients to the embryo during its early stages of development.
-
Production by the Placenta: Once the placenta develops sufficiently (around 8-10 weeks of pregnancy), it takes over the production of progesterone and estrogen, and the corpus luteum is no longer essential. hCG levels then start to decline.
-
Basis for Pregnancy Tests: hCG is produced only during pregnancy, making it a reliable marker for pregnancy tests. Home pregnancy tests detect hCG in urine, while blood tests performed in a medical setting can detect even lower levels of hCG, providing earlier and more accurate results.
In summary, hCG is crucial for the establishment and maintenance of early pregnancy in females by ensuring adequate hormone production to support the developing embryo and preventing menstruation.
