HCG is a hormone that is produced almost exclusively during pregnancy and plays a vital role in the preservation of the embryo until the placenta is formed. Home pregnancy tests work by detecting the presence of Human chorionic gonadotropin in the urine. The Human chorionic gonadotropin is produced in very small quantities in non-pregnant women and men and does not appear to have role or body function. Some cancer types in males and non-pregnant females may also cause the Human chorionic gonadotropin level to rise above average.
Human chorionic gonadotropin known as the pregnancy hormone is a hormone that is produced in large amounts and present in the urine of a pregnant woman, with its level rising at the first 8 – 11 weeks of gestation, and can be detected using one of the various at-home pregnancy tests.
Although not only pregnant women produce a high level of Human chorionic gonadotropin, certain cancer, and other diseases can cause the level of Human chorionic gonadotropin to rise in both men and non-pregnant women.
In This Article
- 1 What exactly is HCG?
- 2 How Early Can hCG Be Detected In The Urine?
- 3 Role of Human Chorionic Gonadotropin in Pregnancy
- 4 What Are The HCG levels in non-pregnant Women or Men?
- 5 What does Human Chorionic Gonadotropin do?
- 6 What problems can arise with HCG?
- 7 How Human chorionic gonadotropin Works As A Pregnancy Test?
What exactly is HCG?
Whether you know it or not, the abbreviation stands for human chorionic gonadotropin, a pregnancy-related hormone. It is what triggers the home pregnancy tests to bring you the good news about the pregnancy.
If you are not pregnant, your body does not have Human chorionic gonadotropin. After conceiving and embryo implantation has taken place in the uterus, the placenta begins producing Human chorionic gonadotropin, which secretes estrogen and progesterone, the other two hormones necessary to protect and sustain a pregnancy. Human chorionic gonadotropin is excreted in the urine, so those pee-on-a-stick tests can determine its presence. Levels start at zero and increase as the embryo grows and continues to increase for 8-11 weeks after pregnancy. So if the test detects Human chorionic gonadotropin, you will receive a positive pregnancy test.
How Early Can hCG Be Detected In The Urine?
It depends on the tests, says an assistant professor of Clinical Obstetrics and Gynecology at Keck Medicine, USC, Sara Twogood. One study found that the first response was positive in 25% of women, six days before their expected period, but different experiments had different sensitivities. In that study, all pregnancy studies examined were 100% correct five days after the first planned day of the period. “In general, we recommend waiting for few days after a missed period before doing a pregnancy test so as to be more accurate, says Sara Twogood. “Testing too early can lead to false-negative results, which means that the woman is pregnant, but Human chorionic gonadotropin levels are too low to be positive.”
Role of Human Chorionic Gonadotropin in Pregnancy
“In its normal form, Human chorionic gonadotropin is almost exclusively produced by a pregnant woman who is part of her placenta and has a cell called a syncytiotrophoblast, which is why its level is increased in pregnancy, says Dr. Kristiner Mixer, MD at Spectrum Health.
The main function of Human chorionic gonadotropin during pregnancy is to support the production of progesterone through the ovaries until the placenta is adequately formed and can usually produce sufficient progesterone alone, usually around the 10th or 11th week of pregnancy.
This is important because progesterone is essential for healthy reproduction. It is responsible for the successful attachment of an embryo within the uterus, modulating the immune system to prevent abortion and uterine contractions. In some cases with repeated pregnancy loss, healthcare professionals sometimes prescribe progesterone or hCG to support early pregnancy. After fertilization, the body starts producing hCG as soon as the fertilized egg implants into the uterine wall. Typically, it takes 8-14 days for hCG levels to increase that much, which can be determined by a home pregnancy test. Most urine pregnancy tests recognize the first missed gestation period.
The Role of Human Chorionic Gonadotropin (hcg) in Molar Pregnancy
A woman may have high levels of hCG even after molar pregnancy. A molar pregnancy occurs after fertilization of the egg, but tissue growing normally in the placenta produces abnormal growth. Therefore, the egg is never developed into an embryo.
Women often remove the molar tissue, but sometimes they can go back and turn into a uterine tumor. This can lead to certain types of cancer, such as choriocarcinoma and malignant gestational trophoblastic disease. Since these tumors are involved in the same cells that produce hCG, women with these conditions often have high levels of Human chorionic gonadotropin even when they are not pregnant.
What Are The HCG levels in non-pregnant Women or Men?
Concentrations are generally very low in non-pregnant women or men and have no effect on daily hormonal function. Although, certain conditions may cause moderate to a high level of hCG in a man or a non-pregnant woman. For example:
- Response to chemotherapy.
- Familial hCG, a very rare genetic disease.
- Gestational Trophoblastic Disease, associated with very high Human chorionic gonadotropin levels.
“All these diseases need to be discussed and treated with a doctor or healthcare professional,” says Mixer.
In addition to diseases that can lead to high HCG levels, hCG injections lead to high hCG levels. “We often see an increase in testosterone production in male athletes,” says Mixer. This is because the Human chorionic gonadotropin is very similar to the pituitary hormone LH, which stimulates testosterone production in the testicles. HCG can also be used as an identification marker during pregnancy to identify Down syndrome. “It is possible to measure a particular hCG subtype to determine the possibility of Down syndrome in the fetus,” says Mixer.
Some types of cancers can cause the levels of hCG to rise higher than normal in both men and women. Cancer types that can lead to high hCG levels include testicular, ovarian, liver, stomach, and lungs.
Measuring chorionic gonadotropin levels in previous cancers can help identify tumors in the body, diagnose cancer, or evaluate the success of cancer treatment.
What does Human Chorionic Gonadotropin do?
As the embryo continues to develop, the level of hCG increases every two to three days. HCG values peak at the sixth week of pregnancy. Later, hCG is found in your body, but levels begin to drop. Once the placenta has fully developed, it acts as a source for progesterone production, and it is no longer necessary for hCG to support ovarian function.
What problems can arise with HCG?
Very high hCG values are rare. So in this case, it may be a sign of molar pregnancy, which is abnormal cell growth in the placenta. In non-pregnant people, high hCG options may be due to certain cancers such as breast, kidney and lung cancer.
At low hCG, there may be a miscarriage or other problems of pregnancy, e.g. Implantation of embryos outside of the uterus.
How Human chorionic gonadotropin Works As A Pregnancy Test?
Many women have very low levels of Human chorionic gonadotropin in their blood and urine when they’re not pregnant. Human chorionic gonadotropin tests recognize a slight increase in the level of hCG in their blood when pregnant. Tests may not detect pregnancy until HCG reaches a certain level. This requirement comes to the early pregnancy diagnostic tests that detect low Human chorionic gonadotropin levels.
Blood tests are more sensitive than urine tests. However, there are many home urine tests that are extremely sensitive. A 2014 analysis found that four home pregnancy tests could detect Human chorionic gonadotropin levels up to 4 days before their expected period or around 10 days after their ovulation.