Are You Pregnant? Signs & Symptoms What is Human Chorionic Gonadotropin (hCG)? By Krissi Danielsson Krissi Danielsson Krissi Danielsson, MD is a doctor of family medicine and an advocate for those who have experienced miscarriage. Learn about our editorial process Updated on November 02, 2020 Medically reviewed Verywell Family articles are reviewed by board-certified physicians and family healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Brian Levine, MD, MS, FACOG Medically reviewed by Brian Levine, MD, MS, FACOG Brian Levine, MD, MS, FACOG, is board-certified in obstetrics-gynecology, as well as reproductive endocrinology and infertility (REI). He is the director and founding partner of CCRM New York and was named a rising star by Super Doctors from 2017 to 2019. Learn about our Medical Review Board Print Peter Dazeley / Getty Images Table of Contents View All Table of Contents What is Human Chorionic Gonadotropin (hCG)? Why It's Important Uses for HCG Tips What is Human Chorionic Gonadotropin (hCG)? Human chorionic gonadotropin, commonly known as hCG, is a hormone found in women's blood and urine throughout pregnancy. HCG becomes detectable in blood shortly after implantation of the embryo in the uterus (roughly three weeks into a four-week menstrual cycle). Increasing levels of hCG tell the body that you are pregnant, putting the womb to work creating a safe home for your baby to grow in. Why It's Important When an embryo forms, it begins making hCG, which facilitates the production of other important pregnancy hormones like progesterone and estrogen. This causes the lining of the uterus to thicken and increase its blood supply, so it can receive the embryo and feed it after implantation. The correct balance of these essential hormones is key for a healthy pregnancy and development of your baby. Pregnancy Tests Home pregnancy tests work by finding hCG in the urine. In early pregnancy, the detectable levels of hCG should double roughly every two days. The hormone becomes detectable in the urine around the time of the first day of a missed menstrual period. For optimal accuracy, wait several days after a missed period before taking a pregnancy test. In early pregnancy, doctors might use one of two types of blood tests to check a woman’s levels of hCG. The most common is a quantitative hCG blood test, which evaluates the level of hCG in the woman’s blood and returns a number. The measurement is reported in units called milli-international units of hCG per milliliter of blood (mIU/mL). HCG levels can vary dramatically from woman to woman and from pregnancy to pregnancy. However, generally, an hCG level of less than 5 mIU/ml means a woman is not pregnant and anything above 25 mIU/ml indicates a pregnancy has occurred. Pregnancy Complications HCG levels are instructive in alerting doctors to possible pregnancy complications, including miscarriage. Women whose hCG levels fall over a period of two to three days in the first trimester in two quantitative hCG blood tests are often advised that this signals an impending miscarriage. This is especially true for women with other miscarriage symptoms, such as vaginal bleeding during pregnancy. HCG levels that rise slowly or decline can be a clue to an impending miscarriage. Decreasing hCG levels later in pregnancy, such as in the second and third trimester, are probably not a cause for concern. Most doctors do not check serial quantitative hCG levels for purposes of evaluating the progress of a pregnancy after the first trimester, although single hCG levels might be checked as a part of the alpha-fetoprotein (AFP) prenatal screening test, which looks for possible birth defects. Normal hCG Levels in Early Pregnancy Uses for HCG This hormone can also be taken as prescription medicine for multiple uses, primarily relating to fertility treatments. HCG is approved by the Food and Drug Administration (FDA) for the treatment of female infertility and other medical uses. It's also marketed for weight loss, but it's not approved for that purpose. Causes and Treatments of Female Infertility Fertility Aid Men can take hCG to boost their sperm production. Women can take it to prompt ovulation, often in conjunction with scheduled intercourse or a variety of fertility treatments, such as intrauterine insemination (IUI) and in vitro fertilization (IVF). Studies show that taking hCG can boost fertility, increasing pregnancy rates and the success of many fertility procedures. When used to treat infertility, the exact type and quantity of hCG prescribed, as well as your specific fertility treatment protocol, will be tailored to your (and your partner's) individual medical needs. In the case of fertility treatment for women, pre-filled hCG syringes (or ones that you prepare yourself) may be given to women to inject at home before or after intercourse and/or fertility treatments. Your doctor will provide detailed instructions on when and how to administer these shots. It's important that hCG only be taken as prescribed and directed by your physician. Methods of Artificial Insemination Avoid HCG Weight Loss Products HCG has not been approved for weight loss or for any over-the-counter uses. However, there are numerous untrue and misleading claims out there that hCG works for weight loss—and numerous hCG supplements are marketed using these spurious claims. Do not buy them, as there is no credible evidence to back up these assertions. In fact, the FDA calls these products "dangerous" and "unhealthy." Tips If you are having your hCG levels tested, you'll want to have a general sense of what to expect and how results are interpreted. Most importantly, while general ranges provide an idea of what is "normal," the results of one hCG blood test mean very little. Rather, the change in the level between two consecutive tests done two to three days apart is much more telling about how a pregnancy is progressing. Quantitative Tests Quantitative hCG blood tests can provide useful information about miscarriage symptoms in the first few weeks after conception. Comparing levels from two quantitative hCG blood tests to look at the hCG doubling time over two to three or more days can give a strong indication of whether or not the pregnancy is progressing as it should be at that point in time. Qualitative Tests Doctors may also use qualitative hCG blood tests. These simply return a yes or no answer on whether or not the woman has hCG in their blood. As hCG levels begin to rise after implantation of an embryo, this test gives you a good sense of if that has happened. It does not tell you how much hCG is in your system or if it is rising or falling, just if there is a detectable amount of the hormone in your blood. What Is Fertility? A Word From Verywell For the most part, during routine pregnancies, the main time you'll be interested in your hCG levels is when you take your pregnancy test. Otherwise, assuming the pregnancy develops optimally, there's nothing you need to do or pay attention to regarding your hCG levels. On the other hand, when fertility issues are at play and/or when you want to know whether or not a pregnancy is progressing normally, monitoring hCG levels can be instrumental in helping you know what's going on—and getting pregnant. 16 Truths About Getting Pregnant and Ovulation Was this page helpful? Thanks for your feedback! Get diet and wellness tips to help your kids stay healthy and happy. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 6 Sources Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Cole LA. hCG, the wonder of today's science. Reprod Biol Endocrinol. 2012;10:24. doi:10.1186/1477-7827-10-24 Korevaar TI, Steegers EA, de Rijke YB, et al. Reference ranges and determinants of total hCG levels during pregnancy: The Generation R Study. Eur J Epidemiol. 2015;30(9):1057–1066. doi:10.1007/s10654-015-0039-0 Konrad G. First-trimester bleeding with falling HCG: Don't assume miscarriage. Can Fam Physician. 2007;53(5):831–832. PMID: 17872745 Barnhart KT, Guo W, Cary MS, et al. Differences in serum human chorionic gonadotropin rise in early pregnancy by race and value at presentation. Obstet Gynecol. 2016;128(3):504-511. doi:10.1097/AOG.0000000000001568 U.S. Food and Drug Administration. Avoid dangerous hCG diet products. Järvelä IY, Tapanainen JS, Martikainen H. Improved pregnancy rate with administration of hCG after intrauterine insemination: A pilot study. Reprod Biol Endocrinol. 2010;8:18. doi:10.1186/1477-7827-8-18