HCG is a hormone that plays an important role in pregnancy. But high or low levels of hCG can indicate certain health issues in anyone.

The full name of this hormone is human chorionic gonadotropin (hCG).

In this article, we look at hCG in detail — including normal ranges during pregnancy, what happens when levels fluctuate, and how doctors use the measurements to identify underlying health conditions.

A doctor checks her pregnant patient's hcg levels.Share on Pinterest
A doctor may measure a person’s hCG level during pregnancy to identify any underlying health problems.

This naturally occurring hormone is present in males and females. But it is usually associated with pregnancy because it plays a key role.

To maintain a pregnancy, hCG triggers the body to produce another hormone, progesterone. It can also help:

  • promote the development of new blood vessels in the uterus
  • smooth the muscle cells in the middle layer of the uterine wall, which is important for maintaining pregnancy

A person may be familiar with hCG because it is the hormone that pregnancy tests check for in urine. A home test can first detect hCG levels that indicate pregnancy about 12–14 days after conception.

A doctor can also check for pregnancy by ordering a blood test to measure hCG levels.

Testing the level of hCG in the blood can also help a doctor identify certain underlying health conditions, including some cancers, and check how effective cancer treatment is.

Levels of hCG can vary widely from one pregnant woman to another.

A test gives an hCG measurement in units per liter (U/l).

Below, find typical levels of hCG throughout pregnancy:

Week since last menstrual periodStandard hCG range (U/l)
40–750
5200–7,000
6200–32,000
73,000–160,000
8–1232,000–210,000
13–169,000–210,000
16–291,400–53,000
29–41 940–60,000

During the first 8 weeks of pregnancy, concentrations of hCG in the blood and urine usually double every 24 hours.

Levels of the hormone typically peak at around 10 weeks, decline until 16 weeks, then remain constant.

During pregnancy, low levels of hCG are not always a cause for concern. This finding may only indicate that there could be a health issue to investigate.

Other times, low hCG can point to a more serious problem. According to a 2018 study, hCG levels were significantly decreased in pregnant women who went on to experience pregnancy loss.

Learn more about pregnancy loss.

Low hCG can also indicate that the fetus is not growing appropriately. A 2017 study found that low hCG was associated with decreased fetal growth and lower birth weight.

There is no treatment for hCG levels that are low.

Find out more about low hCG levels.

As with low levels, high levels of hCG do not necessarily indicate a problem with a pregnancy. Some women simply have higher levels.

If a woman has high hCG levels, it could point to twins or triplets, though only a scan can confirm this.

Sometimes, above-average levels of hCG indicate a higher chance of Down syndrome. A doctor can use blood tests and scans to check.

Gestational trophoblastic disease

One medical concern about higher levels of hCG is that they may indicate gestational trophoblastic disease (GTD).

GTD can occur during or after pregnancy. It causes abnormal cells to grow in the uterus. Some can be cancerous, though most are benign.

Treatment depends on the mass of cells and whether it is cancerous or benign.

To remove the mass, the doctor may recommend dilation and curettage, which involves sucking away the mass with a surgical vacuum and gently scraping away any remaining abnormal cells.

Or, a doctor may recommend a hysterectomy, to remove the uterus.

After the removal, a person may need chemotherapy or other treatment. This may be more likely if hCG levels remain high.

Preeclampsia

High hCG levels may also indicate preeclampsia, a pregnancy-linked condition that involves swelling and a sudden rise in blood pressure.

In a 2012 study, for example, researchers found that hCG levels were significantly increased in women with severe preeclampsia.

It may be safe for a woman with mild preeclampsia to wait and deliver as usual. But if a woman develops the condition and the pregnancy is at 34–37 weeks or later, it may be necessary to induce delivery.

Treatment tends to involve close monitoring, which may need to take place in a hospital, as well as medication to control blood pressure and prevent seizures.

Learn more about preeclampsia.

Normal levels of hCG are typically undetectable in females who are not pregnant and in males.

Higher levels can sometimes point to an underlying health problem, such as:

A 2011 study found that males with reduced sperm count and other issues related to semen had significantly lower levels of hCG.

Doctors sometimes prescribe hCG to combat the symptoms of conditions such as hypogonadism, in which the testes do not produce enough testosterone, sperm, or both.

Pregnant women experiencing vaginal bleeding or abdominal cramps should receive medical attention.

Everyone should see a doctor if they:

  • are having difficulty conceiving
  • notice a lump in their breasts or testicles
  • have blood in their urine, stool, vomit, or phlegm
  • have a cough that does not go away, breathlessness, or chest pain
  • notice changes in bowel movements
  • have unexplained weight loss
  • notice skin changes, such as moles that change shape or bleed

HCG is a hormone that everyone has.

It plays a key role in pregnancy, during which levels rise significantly. Especially high or low levels during pregnancy can indicate a problem, but this is not always the case.

In other people, high levels of hCG sometimes indicate an underlying health condition, possibly one that affects fertility.