hCG is the hormone that is produced by the placenta in early pregnancy. After fertilization has taken place, a rise in hCG is typically the first sign of pregnancy. During the first trimester, your hCG levels will double every two to three days indicating a healthy pregnancy. If your levels don’t double or begin to drop, then this may indicate a problem with the pregnancy like a miscarriage.
What is hCG?
Human Chorionic Gonadotropin (hCG) is the hormone produced by the placenta to support a pregnancy and is also known as the “pregnancy hormone”. This is the hormone that an at-home urine pregnancy test detects and will show positive if the hormone is present – indicating you are pregnant!
There are two different ways to measure hCG levels: through urine or blood. hCG in urine is qualitative, meaning an at-home pregnancy test will tell you if hCG is present or not, but it does not give you an exact amount of hCG. To get a quantitative result – meaning an exact amount of hCG present in the blood (ie. 100, 250, 1000 mIU/mL) – you would need to have blood work done as ordered by your provider. This is also known as a beta blood draw.
hCG levels in early pregnancy
A healthy pregnancy will show quick-rising levels of hCG throughout the first trimester. During early pregnancy, hCG levels will begin to double every two to three days as the placenta begins to develop. A positive pregnancy hCG result is considered to be anything above 25 mIU/mL, and a negative result is considered to be anything below 5 mIU/mL. Anything between 5-25 mIU/mL is considered a gray area and will need to be retested for clarification.
Here is a hCG levels chart by week during early pregnancy according to experts. To get a better understanding of the progression of your hCG levels, you should set an appointment with your healthcare professional.
*These numbers are a guideline of hCG levels; it is important to note that hCG can rise differently from person to person. Values can also vary from laboratory to laboratory. Always talk to your provider about the meaning of your test result.
Can hCG levels fluctuate?
There can be a wide variety of hCG levels in a healthy pregnancy, however, the most important thing is that the hormone continues to rise appropriately. hCG levels will not necessarily fluctuate, meaning they will not go up and down during a healthy pregnancy. We want to continue to see those levels get higher every few days; not get lower. Low hCG levels or a drop in levels during early pregnancy could mean a problem with the pregnancy like a miscarriage.
hCG levels should be doubling about every 2-3 days in the first trimester, and they will eventually decrease and plateau during the second trimester. hCG levels will rise at different paces from woman to woman, and even from pregnancy to pregnancy for the same woman. Although the numbers do matter, what is most important is that the hormone rises appropriately over a certain amount of time, not necessarily how high or low your result is.
Three causes for low hCG levels
Everyone’s biggest fear when testing. We anxiously wait for our next pregnancy test, making sure the line is getting darker, but that does not always happen. Low hCG levels in pregnancy could occur because of any of the following reasons:
- False positives: Yes, I know what you’re thinking, how is this even allowed? Completely unfair, but completely possible. False positives are rare, but they can happen if the product you are using is faulty, expired, or damaged.
- Chemical pregnancy: A chemical pregnancy – a very early miscarriage – is when fertilization takes place and hCG is produced, but for some reason, it doesn’t stick. When this happens, hCG quickly goes down within a few days and oftentimes before your missed period. Chemical pregnancies happen so early that some women don’t even know it happened because they are not testing as early as others. For those of us who do test early, this may be one reason a pregnancy test line would get fainter instead of darker.
- Miscalculation of pregnancy: If your first level of hCG comes back lower than expected for your gestational age, it could be due to a miscalculation; meaning maybe you ovulated a little later than expected and are not as far along as you thought. With this type of low result, we would still expect to see the hormone continue to double appropriately over 2-3 days.
Pregnancy Test Line Progression
When testing at home using urine pregnancy strips, you may get your first positive pregnancy test at around 10 days post-ovulation. Although this is very early, not all women will see a positive in their urine that soon. Many do not get a positive until closer to 12-14 days post ovulation.
Once you do get your first positive, you can use the Premom app to capture an image of your pregnancy tests to have a safe place to track your pregnancy test line progression. On Premom or Easy@Home pregnancy tests, you should see your test line begin to darken every 2-3 days as a sign of the pregnancy hormone strengthening.
Not all women choose to track their line progression because it can cause added stress or anxiety waiting to see your line get darker, but some women do enjoy watching their hCG double. After you see your positive and schedule your first visit with your OB/GYN, you do not need to continue testing.
Once you do get your first positive urine pregnancy test be sure to call your OB/GYN to set up your first appointment for recognition of pregnancy either through a beta blood draw or an ultrasound.
While you wait for your first prenatal visit, be sure to switch to Premom’s Pregnancy Mode to get a comprehensive overview of your pregnancy timeline, including a due date calculator, fetal development tracker, and symptom checker. Get helpful tips and advice on nutrition, exercise, and lifestyle changes all from real experts. Continue your pregnancy journey with Premom.
Frequently Asked Questions
Q: What are hCG levels at 3 weeks pregnant?
At 3 weeks pregnant, your hCG levels should be roughly 5 – 50 mIU/mL.
Q: What are hCG levels at 4 weeks pregnant?
At 4 weeks pregnant, your hCG levels should be roughly 5 – 426 mIU/mL.
Q: What are hCG levels at 5 weeks pregnant?
At 5 weeks pregnant, your hCG levels should be roughly 18 – 7,340 mIU/mL.
Q: What are hCG levels at 6 weeks pregnant?
At 6 weeks pregnant, your hCG levels should be roughly 1,080 – 56,500 mIU/mL.
What hCG levels indicate pregnancy?
A positive hCG result is considered to be anything above 25 mIU/mL on an at-home pregnancy test.
References
- Editor. What is HCG? American Pregnancy Association. https://americanpregnancy.org/getting-pregnant/hcg-levels/. Published May 31, 2022. Accessed February 6, 2023.
- HCG levels during pregnancy: What’s normal? – endocrineweb.com. https://www.endocrineweb.com/pregnancy/hcg-levels-during-pregnancy. Accessed February 6, 2023.
- Human chorionic gonadotropin: Hormone, purpose & levels. Cleveland Clinic. https://my.clevelandclinic.org/health/articles/22489-human-chorionic-gonadotropin. Accessed February 6, 2023.
