Human Chorionic Gonadotropin (hCG) Levels Explained

Human chorionic gonadotropin (hCG) is a hormone that plays a vital role in pregnancy. Often called the pregnancy hormone, it starts rising soon after implantation and can be detected through a pregnancy test. Whether you're wondering what hCG is, when it starts to rise, or what normal levels look like, this guide will help answer your questions.

Key Takeaways:

• What is hCG? A hormone produced during pregnancy that supports early fetal development.

• When does hCG start to rise? About 10 days after conception, with levels increasing rapidly in early pregnancy.

• How is hCG measured? Through an hCG blood test or a home pregnancy test that detects the hormone in urine.

• What hCG level indicates pregnancy? Typically, an hCG level of 25 mIU/mL or higher confirms pregnancy.

• What are normal hCG levels by week? Levels vary, but our hCG level chart can help you understand how they may rise and fall during pregnancy.

• When does hCG peak? Around weeks 8–11 before gradually declining.

• What if hCG levels are too low or too high? Levels that don’t follow the expected pattern may require further evaluation by your healthcare provider.

This article covers everything from hCG beta quantitative tests to understanding hCG levels by week—helping you confidently navigate your pregnancy.

What Is hCG?

Human chorionic gonadotropin (hCG) is known as the pregnancy hormone because your body produces it in large amounts when you’re pregnant.

While low levels of hCG can be present in your body at any time, this hormone sees a sharp increase early in pregnancy. Below we answer the common questions about when and where hCG is produced during pregnancy:

• When does hCG start to rise? About 10 days after conception, the fertilized egg attaches to the lining of your uterus and your body starts to make hCG. This early surge can often be detected through an hCG beta quantitative blood test, which measures the exact levels of the hormone. Over the next week, hCG levels continue to rise significantly.

• By about 4 weeks pregnant, the egg—now called an embryo—implants further into the uterus and begins to produce even more hCG. This surge triggers increased production of other essential hormones like estrogen and progesterone.

• What does hCG do in early pregnancy? One of hCG's key roles is to support the early stages of pregnancy. It helps maintain the uterine lining and signals the ovaries to stop releasing eggs, effectively preventing your period. 

• Where is hCG produced? The hormone is primarily made by the cells of the developing placenta, ensuring the pregnancy continues to progress.

During these early weeks of pregnancy, you may not show any outward signs of being pregnant and you may not even suspect that you’re pregnant! You may, however, experience implantation bleeding when the fertilized egg attaches to the lining of the uterus (as described above). This is normal and may resemble spotting or a light period.

How and Why is hCG Measured During Pregnancy?

Measuring hCG levels during pregnancy provides valuable information about the health and progression of your pregnancy.​

How is hCG measured?

There are two primary methods to measure hCG:​

1. Urine tests. Commonly used in home pregnancy tests, these detect the presence of hCG in urine. They are qualitative, indicating simply whether hCG is present or not.​

2. Blood tests. Performed in a medical setting, these can be either qualitative or quantitative. A quantitative beta hCG test measures the exact amount of hCG in the blood, providing more detailed information about the pregnancy’s progression.

Why is hCG measured during pregnancy?

Monitoring hCG levels serves several purposes:​

• Confirming pregnancy. Detecting hCG is one of the earliest indicators of pregnancy, as this hormone is produced shortly after implantation. ​

• Assessing pregnancy progression. In early pregnancy, hCG levels typically double every two to three days. Measuring these levels can help determine if the pregnancy is developing normally. 

• Diagnosing potential complications. Abnormal hCG levels may indicate issues such as ectopic pregnancies or potential miscarriages. For instance, lower-than-expected hCG levels can be a sign of early pregnancy loss.

• Screening for genetic disorders. Between the 15th and 20th weeks of pregnancy, the quad screen blood test measures hCG along with other substances to assess the risk of certain genetic conditions, such as Down syndrome. 

By measuring hCG levels through these methods, your healthcare provider can gather essential information to support the health and well-being of both you and your developing baby.

When Can Pregnancy Tests Detect hCG?

Home pregnancy tests often work by detecting hCG in your urine. As we mentioned earlier, hCG typically begins increasing about 10 days after conception, but levels may still be too low to detect immediately.

The timing of a pregnancy test affects its accuracy, as hCG levels increase over time. If taken too early, a test might not detect low levels of hCG, leading to a false negative. Here’s a general guideline:

• Early testing (before a missed period). Some pregnancy tests detect hCG as soon as 6 to 8 days after ovulation, but accuracy improves with time.

• Testing around your missed period. The best time to test hCG with a pregnancy test is on or after the first day of a missed period, as pregnancy hormone levels will be higher and more detectable.

• Later testing (after a missed period). By this point, hCG levels have increased significantly, making detection more reliable.

A blood test is the most accurate way to detect hCG levels because more of the pregnancy hormone is present in the blood than in the urine. Plus, blood tests need less of the hCG hormone to detect a pregnancy, as explained below:

• Blood tests can detect very low levels of hCG (5 to 10 mIU/mL), making them the earliest and most sensitive option. 

• Urine tests require higher pregnancy test levels of hCG detection, typically 20 to 25 mIU/mL.

If your home test is positive, your healthcare provider may perform a blood test to confirm the pregnancy and estimate how far along you are.

If you’ve just found out you’re pregnant, you can get an estimate of your due date with our Due Date Calculator using either the date of conception or the date of the first day of your last menstrual period!

If you’ve just found out you’re pregnant, you can get an estimate of your due date with our Due Date Calculator using either the date of conception or the date of the first day of your last menstrual period!

How Often Should You Test for hCG?

Monitoring hCG levels during early pregnancy is crucial for evaluating the health and progress of the pregnancy. Typically, in early pregnancy, hCG levels double approximately every 48 to 72 hours. If your healthcare provider suggests monitoring your hCG levels, tests are usually conducted every two to three days to track this expected increase. This monitoring helps ensure that the pregnancy is progressing normally and can identify any potential complications. It is common to have hCG levels checked only once or twice during a typical early pregnancy. 

Normal hCG Levels in Pregnancy: Chart by Week

The week-by-week chart below will give you an idea of how your hCG levels may rise during the first trimester, and then dip slightly during the second trimester. For example, if you’re 4 weeks pregnant, your hCG levels might be between 10 to 708 mIU/mL, while at 6 weeks pregnant, they may be between 152 to 32,177 mIU/mL. 

Keep in mind that, if you want your hCG blood test results explained in more detail, your healthcare provider is the best person to ask.

What Do the Levels of hCG Mean?

It’s important to remember that every pregnancy is different, and you may have lower or higher levels of hCG hormone than what’s indicated in the week-by-week chart above. Most likely, there’s no cause for concern, but your healthcare provider will help you understand what these levels mean.

Low Levels of hCG

Low levels of hCG are normal for non-pregnant women and men. Normally, hCG levels would be less than 5 mIU/mL and less than 2 mIU/mL, respectively, for these groups.

If you’re pregnant and experience low hCG levels, it’s important to look at your entire pregnancy as a whole. Your healthcare provider will consider all the factors of your pregnancy to determine why you might be experiencing lower-than-normal levels of hCG. If your provider suspects anything like an ectopic pregnancy, they may perform additional tests to rule it out.

High Levels of hCG

Likewise, high levels of the hCG hormone might not indicate anything out of the ordinary. However, the reasons for high hCG levels in early pregnancy might be a twin pregnancy or triplets! Again, your healthcare provider will work with you to determine an appropriate course of action, if any is needed. 

Lower- or higher-than-normal levels of the hCG hormone during your pregnancy might not indicate anything unusual. However, it’s always a good idea to follow up with your healthcare provider as a precaution, regardless of any questions or concerns you have. Read more about other pregnancy symptoms not to ignore. 

When to Consult Your Healthcare Provider

Healthcare providers typically check hCG levels early in pregnancy to confirm and monitor its progression. However, routine hCG testing is not usually needed unless there are specific concerns about the pregnancy.

Your provider may decide to recheck hCG levels if:

• The initial hCG measurement is lower than expected based on the gestational age.

• There are signs of potential pregnancy complications, such as unusual cramping, bleeding, or other symptoms.

• Additional testing, such as an ultrasound, is needed to confirm the health of the pregnancy.

If your provider has concerns, they may perform repeat hCG tests over a few days to track how levels are changing. Since hCG levels naturally vary, a single measurement is not always enough to determine a problem—what matters most is how the levels increase over time.

For any concerns about hCG levels or pregnancy symptoms, it's always best to consult your healthcare provider for personalized guidance.

The Bottom Line

The hCG hormone plays an important role in your pregnancy, and the changing levels of this hormone are just one of many transformations your body will experience as your baby develops.

Although hormonal changes can make you feel a little off from time to time during your pregnancy, try to take these as reassurance that your baby is growing, and you’re getting closer and closer to the day you finally get to meet them.

In the meantime, prepare for your baby’s arrival and get rewards on all your diapers and wipes purchases with the Pampers Rewards app!

Ready to share your pregnancy news with friends and family? Get creative pregnancy announcement ideas in the video below!