Understanding Human Chorionic Gonadotropin (hCG) Levels During Pregnancy
Human chorionic gonadotropin (hCG) is a hormone that is normally produced in the cells by the placenta. During pregnancy, this hormone is produced in large quantities which is why hCG is often referred to as pregnancy hormones. These hormones help you detect your pregnancy at home using pregnancy tests which are designed to do so.
Read on to know more about what hCG is, what does hCG levels mean, when it’s detectable by at-home pregnancy tests, and what the typical hCG levels in pregnancy are for each of the early weeks of pregnancy.
What Is hCG?
Human chorionic gonadotropin, hCG for short, is a hormone that is produced in large amounts during your pregnancy period. Many home pregnancy tests often work by detecting hCG levels in your urine.
In the initial weeks of your pregnancy, the embryo produces more hCG along with other hormones like estrogen and progesterone. These hormones aid in building up the lining of the uterus and send signals to the ovaries to stop releasing eggs, thereby stopping your period.
But keep in mind that even non-pregnant women and healthy men also have low levels of hCG. Normally, the hCG levels would be less than 5 mIU/mL and less than 2 mIU/mL for these groups, respectively.
When Does Your Body Start Producing hCG?
As mentioned earlier, your body already has certain hCG levels. But when a fertilised egg implants in your uterus, these hCG levels begin to grow rapidly. Usually, the spike in your hCG levels occurs about ten days post-conception. In these early weeks of your pregnancy, you might not even know that you’re pregnant as you may not experience any signs or symptoms of pregnancy. However, you may experience implantation bleeding when the fertilised egg attaches to the lining of the uterus. This is quite normal and may look like spotting or a light period flow.
When Can Pregnancy Tests Detect hCG?
All over-the-counter pregnancy tests work a little differently, so you should check the instructions in or on the box. Keep in mind that hCG levels increase over time, so pregnancy tests are more accurate as time goes on.
You might try taking a pregnancy test about three to four weeks after the first day of your period, as this is when the levels of hCG in your urine will have increased enough to be detected. You might like to wait until around the time you miss your first period, which may be when you first start to suspect that you may be pregnant anyway.
Taking the test too early may mean you get a false negative — that is, the result may be negative when you are actually pregnant. This may occur because very early on in your pregnancy, the levels of hCG may be so low that an at-home pregnancy test might not be sensitive enough to pick up on the hormone.
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. Blood tests can detect levels between 5 and 10 mIU/mL versus the 20 mIU/mL that most at-home pregnancy tests can detect.
If your home pregnancy test is positive, your doctor may offer a blood test to check your hCG levels. The results can help your doctor confirm your pregnancy and determine how far along you are.
A higher-than-normal level of hCG may indicate that you’re having twins or triplets.
If you’ve just found out you’re pregnant, you can get an estimate of your due date with our Due Date Calculator above using either the date of conception or the date of the first day of your last menstrual period.
hCG Levels Chart
This chart will give you an idea of how your hCG levels may rise during the first trimester and then dip slightly during the second trimester. Keep in mind that, if you want your hCG blood test results explained in more detail, your doctor is the best person to turn to.
| Pregnancy week | Range of hCG levels in milli-international units per milliliter (mIU/mL) |
|---|---|
| 3 weeks | 5–72 mIU/mL |
| 4 weeks | 10–708 mIU/mL |
| 5 weeks | 217–8,245 mIU/mL |
| 6 weeks | 152–32,177 mIU/mL |
| 7 weeks | 4,059–153,767 mIU/mL |
| 8 weeks | 31,366–149,094 mIU/mL |
| 9 weeks | 59,109–135,901 mIU/mL |
| 10 weeks | 44,186–170,409 mIU/mL |
| 12 weeks | 27,107–201,165 mIU/mL |
| 14 weeks | 24,302–93,646 mIU/mL |
| 15 weeks | 12,540–69,747 mIU/mL |
| 16 weeks | 8,904–55,332 mIU/mL |
| 17 weeks | 8,240–51,793 mIU/mL |
| 18 weeks | 9,649–55,271 mIU/mL |
What Does It Mean if You Have High or Low hCG Levels?
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, a higher-than-normal level of hCG may be a sign that you’re having twins 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.
Frequently Asked Questions
The Bottomline
During pregnancy, your hCG levels play a vital role as the changing levels indicate that your little one is developing inside your belly. We understand that these hormonal changes can sometimes throw you off and make you irritable. But all you need to remember is that due to these hormones, soon enough you will be blessed with a healthy and happy baby!