The human chorionic gonadotropin (hCG) level in the blood is measured by the beta-hCG test. This hormone is generated as early as 10 days after conception, and an elevated level indicates pregnancy.
What is hCG?
hCG (Human Chorionic Gonadotropin) is a hormone generated and released by the placental syncytiotrophoblast cells. The epithelial coating of the highly vascular embryonic placental villi is called syncytiotrophoblast. It infiltrates the uterine wall, rupturing maternal capillaries and forming a junction between maternal blood and embryonic extracellular fluid. It aids in the material exchange between the mother and the embryo via the placenta.
Both men and women produce hCG. hCG is necessary for the corpus luteum to function properly. In the female reproductive system, the Corpus luteum is a hormone-secreting organ. It is made up of lutein cells and is generated in the ovary. Estrogens and progesterone are secreted by it. hCG stimulates the corpus luteum to generate changes in the uterus that allow the fertilised ovum or egg to implant and the embryo to grow. The corpus luteum degenerates or becomes inactive after 10-14 days if the egg or ovum is not fertilised.
After 8-11 days of conception, hCG can be found in blood tests. hCG levels double every 48-72 hours, with peak levels occurring 8-11 weeks following pregnancy. These levels gradually decrease and stay stable throughout the pregnancy. This hormone can be identified in urine after 12-14 days of missing menstruation.
What is the Beta hCG test used for?
The Beta hCG-Blood Test is used to determine whether an individual’s hCG levels in the blood are normal or abnormal. This test may be ordered by a healthcare professional to confirm pregnancy, assess the appropriate age of the foetus, and detect a possible miscarriage (unintended pregnancy loss). This test is also used to assess the risk of ectopic pregnancy (when a fertilised egg or embryo attaches to the uterine wall outside of the uterus), multiple pregnancies (when a woman has twins, triplets, or more children), and molar pregnancy (when a genetic error occurs during the fertilisation process and abnormal tissues grow within the uterus).
Aside from that, the beta-hCG test can be used to evaluate fertility treatments (a synthetic form of the hormone is occasionally used to assist follicles growing and promote ovulation), and when there are concerns about a pregnancy going terribly wrong. This test is usually done in conjunction with other tests to confirm the diagnosis.
Ovarian cancer (cancer that starts in the ovaries, where eggs develop), testicular cancer (cancer in the testicles of males, where sperm and other male hormones are produced), and choriocarcinoma (fast-growing cancer in the woman’s uterus) are all rare. If a patient is using anti-cancer drugs such as Avastin, cisplatin, or bevacizumab, the doctor can prescribe this test to assess and monitor the treatment’s effectiveness as well as hCG levels in the body. This aids the physician in ruling out the patient’s medical state.
Before beginning a treatment that may impact the embryo or foetus in the pregnant woman, a medical professional may prescribe this test. This test can also be used to screen for Down syndrome and Edward’s syndrome (a disease in which an infant has severe developmental deficits due to an extra chromosome 18). .
The results are expressed in mIU/mL (milli-international units per millilitre). The following are the hCG levels in men and women:
- Women who are not pregnant: fewer than 5 mIU/mL
- Less than 2 mIU/mL in healthy males
The hCG level rises significantly during the first trimester of pregnancy and then gradually decreases. The predicted hCG ranges in pregnant women are determined by the pregnancy’s length.
- 5 – 72 mIU/mL after 3 weeks
- 10-708 mIU/mL after 4 weeks
- 217 – 8,245 mIU/mL after 5 weeks
- 152 – 32,177 mIU/mL after 6 weeks
- 4,059 – 153,767 mIU/mL after 7 weeks
- 31,366 – 149,094 mIU/mL at 8 weeks
- 59,109 – 135,901 mIU/mL after 9 weeks
- 44,186 – 170,409 mIU/mL after 10 weeks
- 27,107 – 201,165 mIU/mL after 12 weeks
- 24,302 – 93,646 mIU/mL at 14 weeks
- 12,540 – 69,747 mIU/mL after 15 weeks
- 8,904 – 55,332 mIU/mL at 16 weeks
- 8,240 – 51,793 mIU/mL at 17 weeks
- 9,649 – 55,271 mIU/mL at 18 weeks