Human chorionic gonadotropin, or hCG for short, is often referred to as ‘the pregnancy hormone’ due to its presence in large quantities during pregnancy. All pregnancy tests work by detecting hCG, which is crucial to the development of a foetus. Read below to learn more about hCG, when it can be detected using at-home pregnancy tests and standard hCG levels during early pregnancy.
What Is hCG and When Does Your Body Start Producing It?
Human chorionic gonadotropin (hCG) is known as the pregnancy hormone, as your body produces it in large amounts when you’re pregnant.
While hCG levels are typically low, they elevate during pregnancy and double approximately every 48 hours in viable early pregnancy:
About 10 days after conception, the fertilized egg attaches to the lining of your uterus and your body starts to make hCG. Over the next week or so, hCG levels will increase.
At about 4 weeks pregnant, the egg—now called an embryo—implants further into the uterus and begins to produce even more hCG, which triggers increased productions of other hormones like oestrogen and progesterone.
Later in pregnancy, around 12 weeks after conception, hCG levels begin to fall as the placenta starts to product steroid hormones.
Together, these hormones help build the lining of the uterus and send signals to the ovaries to stop releasing eggs, ultimately stopping your period.
hCG levels quickly elevate when you become pregnant, especially after the fertilized egg attaches to your uterine lining and the embryo implants into the wall of the uterus. This hormone works together with oestrogen and progesterone to build the lining of the uterus and stop your body from releasing more eggs.
During those first few weeks of pregnancy, you may not show any outward signs of being pregnant and may not even know you’re pregnant yet! However, you may experience some implantation bleeding when the fertilized egg attaches to the lining of the uterus (as described above). Implantation bleeding is totally normal and often comes in the form of light spotting.
When Can Pregnancy Tests Detect hCG?
Home pregnancy tests often work by detecting hCG in your urine. As over-the-counter pregnancy tests all work differently, we recommend reading the instructions on the box. During early pregnancy hCG levels double every two days, so hCG becomes easier to detect as the days progress. This is why it's a good idea to wait until after the first day of your missed period to take the test, as taking the test any earlier may result in a false negative.
Wondering when to take the test? Most home pregnancy tests can be carried out from the first day of a missed period. If you aren’t sure when your next period is due, the NHS recommends waiting at least 21 days since you last had unprotected sex before taking a test.
If you’re look for a more accurate method to detect hCG levels, it may be best to opt for a blood test. Compared to urine tests, blood tests tend to provide more reliable results as more hCG can be found in the blood than in the urine.
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 also require lower hCG levels to detect a pregnancy, as explained below:
Blood tests. Pregnancy blood tests can detect hCG hormone levels as low as 5 to 10 mIU/mL.
Urine tests. At-home urine tests require higher levels of hCG to detect a pregnancy, typically at least 20 mIU/mL.
If your test is positive, contact your GP or a midwife to start your antenatal care and find out how far along you are.
It’s often best to wait until three or four weeks after the first day of your last period before taking a home pregnancy test as they require a higher hCG concentration. For even more accurate results, wait until after you’ve noticed you’ve missed your period. Your GP may then carry out a blood test to confirm you are pregnant.
Get ready for your baby’s arrival by finding out your estimated due date with our Due Date Calculator using either the date of conception or the date of the first day of your last period!
RELATED PREGNANCY TOOL
hCG Levels Chart by Week
The week-by-week chart provides a guide on how your hCG levels may rise during the first trimester, and then dip slightly during the second trimester. Please consult your GP for more information on your personal hCG levels.
|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?
Every pregnancy is different, and the same goes for hCG levels. You may find that you have lower or higher levels of hCG than the ranges in the chart above. There’s likely no reason to worry, but your GP will be able to 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. If you’re pregnant and experience low hCG levels, it’s important to look at your entire pregnancy as a whole. Your GP will consider all the factors of your pregnancy to determine why you might be experiencing lower-than-normal levels of hCG. Additional tests may be required to rule out other causes like ectopic pregnancy.
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High Levels of hCG
Similarly to low levels, high levels of the hCG hormone might not necessarily indicate anything out of the ordinary. However, a higher-than-normal level of hCG may be a sign that you’re having multiples! Your GP 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 discuss any concerns you may have with your GP. Read more about other pregnancy warning signs.
Every pregnancy is different, just like hCG levels. You may find that your hCG levels don’t fall into the range in the above charge. If so, your GP will be able to determine why you may have low or high levels of hCG. High hCG levels may even indicate that you’re expecting multiples!
FAQs AT A GLANCE
Elevated hCG levels above 5 mIU/mL may indicate pregnancy.
hCG works together with oestrogen and progesterone to build the lining of the uterus and stop your body from releasing more eggs. It is also crucial for the development of the foetus.
At 4 weeks pregnant, your hCG levels can range from about 10 to 708 mIU/mL.
hCG levels are not typically high enough to produce accurate results within the first week of pregnancy, so it is recommended to wait at least three to four weeks after the first day of your last period before taking a test.
The Bottom Line
hCG is one of the main pregnancy hormones your body produces in the first trimester, with production doubling every 48 hours during early pregnancy. It’s also responsible for that special ‘pregnancy glow’. Hormonal changes can understandably leave you feeling a little off from time to time during your pregnancy, but they are also there to reassure you that you baby is growing and almost ready to meet you!
How We Wrote This Article
The information in this article is based on the expert advice found in trusted medical and government sources, such as the National Health Service (NHS).The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.
What are normal hCG levels at 5 weeks? At 5 weeks pregnant, your hCG levels can range from about 217 to 8,245 mIU/mL.What should hCG levels be during early pregnancy? ›
The average levels of hCG in a pregnant woman's blood are: 3 weeks: 6 – 70 IU/L. 4 weeks: 10 - 750 IU/L. 5 weeks: 200 - 7,100 IU/L.How do I read my hCG results? ›
An hCG level of less than 5 mIU/mL is considered negative for pregnancy, and anything above 25 mIU/mL is considered positive for pregnancy. An hCG level between 6 and 24 mIU/mL is considered a grey area, and you'll likely need to be retested to see if your levels rise to confirm a pregnancy.How much hCG do you have after implantation? ›
After implantation occurs, hCG levels will double approximately every 48-72 hours. hCG levels will peak within the first 8-11 weeks of pregnancy, and then will begin dropping off from there and plateau for the remainder of pregnancy.What levels of hCG indicate Down syndrome? ›
RESULTS: The median free β-human chorionic gonadotropin and pregnancy-associated plasma protein A levels in cases of Down syndrome was 2.09 (95% confidence interval 1.69 to 2.62) and 0.405 multiples of the median (95% confidence interval 0.28 to 0.67), respectively.What level of hCG indicates twins? ›
The range for singletons is 5 – 397 and for twins it is 48 – 683. As you can see, there is a big overlap between the first hCG level in singleton and twins.Can hCG levels drop then rise in early pregnancy? ›
Sometimes, hCG levels drop, but then rise again and the pregnancy continues normally. Although this is not common, it can happen. Decreasing hCG levels later in pregnancy, such as the second and third trimester, are probably not a cause for concern.What are good numbers for hCG? ›
Normal levels are found in: Non-pregnant women: less than 5 mIU/mL. Healthy men: less than 2 mIU/mL.How do you know hCG test is positive? ›
For most tests, it only takes about 5 to 10 minutes for a result to appear. Typically, a colored line or plus symbol will appear on the test stick to indicate a positive result. The absence of a colored line or a negative sign usually indicates a negative result.How high is hCG 2 weeks after conception? ›
2 Weeks Pregnant HCG Level
Average hCG levels: Less than 10 U/L in non-pregnant women. 10 to 25 U/L for a 'borderline' pregnancy result. more than 25 U/L for a postive result.
It is this hormone that is responsible for a positive pregnancy test. From the time of implantation, HCG hormone levels are approximately 1-2mIU (milli international unit) and double every 48-72 hours. Any HCG level above 25mIU is considered pregnant, while less than 5 is considered not pregnant.How does hCG increase day by day? ›
In the first four weeks of a viable pregnancy, hCG levels will typically double about every two to three days. After six weeks, the levels will double about every 96 hours. So, if your baseline level is higher than 5 mIU/mL, your doctor may order a repeat test a couple days later to see if the number doubles.› getting-pregnant › hcg-le... ›
hCG Levels | The American Pregnancy Association
hCG levels in pregnancy: What do they really mean?
HCG Levels by Week: Normal hCG Levels in Early Pregnancy
In the event of a miscarriage, hCG levels typically decrease from previous measurements. For example, a baseline level of 120 mIU/mL that's dropped to 80 mIU/mL two days later can indicate the embryo is no longer developing and the body isn't producing more hormones to support its growth.How fast should hCG rise at 5 weeks? ›
Typically, hCG levels double every 48 to 72 hours for the first four weeks of a normal pregnancy, then slows to every 96 hours by week 6, and peaks around 10 weeks, before leveling off and remaining constant for the remainder of the pregnancy.What does high hCG levels mean at 5 weeks? ›
High hCG levels could be a sign of gestational trophoblastic disease (GTD) or a molar pregnancy. If your early hCG reading is extremely high, you will need an immediate follow-up appointment to determine the cause.What is hCG for twins at 5 weeks? ›
hCG levels during pregnancy.
|Week||HCG Range (Single)|
|Week 5||18-7,340 mIU/ml|
|Week 6||1,080-56,500 mIU/ml|
|Weeks 7-8||7,650-229,000 mIU/ml|
|Weeks 9-12||25,700-288,000 mIU/ml|
High hCG levels in pregnancy
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, hCG levels drop, but then rise again and the pregnancy continues normally. Although this is not common, it can happen. Decreasing hCG levels later in pregnancy, such as the second and third trimester, are probably not a cause for concern.How fast does hCG drop before miscarriage? ›
A 2013 medical study that tested 443 women who had miscarriages found that hCG levels declined faster than previously thought. The researchers reported there was a 35 to 50 percent reduction in hCG levels 2 days after, and a 66 to 87 percent reduction 7 days after the pregnancy resolved.
In fact, a 2017 study into hCG found that “the slowest or minimal rise for a normal viable intrauterine pregnancy was 24% at one day and 53% at two days. More recently, a rise of 35% over 48 hours was proposed as the minimal increase consistent with a viable intrauterine pregnancy.” Dr.Is it possible to have low hCG levels and still be pregnant? ›
If your hCG levels fall below the normal range, it's not necessarily a cause for concern. Many women have gone on to have healthy pregnancies and babies with low hCG levels. Most women don't ever have cause to find out what their hCG levels are specifically.Can a pregnancy be successful with low hCG? ›
Even if a complication associated with low hCG levels occurs, such as a miscarriage or an ectopic pregnancy, this does not mean that someone will be unable to get pregnant again or that their fertility is compromised. A successful pregnancy is still possible with low hCG levels.What level of hCG indicates twins? ›
The range for singletons is 5 – 397 and for twins it is 48 – 683. As you can see, there is a big overlap between the first hCG level in singleton and twins.Can hCG predict twins? ›
Increased hCG levels can be an indicator of a pregnancy that includes twins, but it's not conclusive evidence. (It could just mean that your pregnancy dates have been miscalculated.)Do twins implant at the same time? ›
Twins can occur in these early stages of fertilization. There are two different types of twins that can form: Fraternal Twins: This type of twin set is the most common. This occurs when two different eggs are both fertilized by two different sperm and implant themselves into the uterine wall at the same time.How long does it take hCG to double at 5 weeks? ›
How often does hCG double? During the first four to six weeks of pregnancy, hCG levels double every two days. After that, it may take three to four days to double until the sixth week.