Your hCG level is the pregnancy hormone your body makes as soon as a fertilised egg implants in your womb. In the first weeks this hormone rises quickly, often roughly doubling every two to three days. Yet a single value tells you little on its own, because levels vary enormously between women. The rise over time tells you more than one reading, and your midwife or GP always looks at the full picture.
I am writing this article because I know how nerve-racking those first weeks are. Maybe you have just had a positive test, or maybe you are waiting on a second blood result and counting the hours. What I most want you to take away: a number is not a prediction, and you do not have to interpret it alone. This article calmly explains what hCG is, what normal weekly values look like and why the trend matters more than a snapshot.
This is the overview article in our hCG series. If you want to work out your own doubling time, use our hCG calculator to compare two results.
What is hCG and what does it do in pregnancy?
hCG stands for human chorionic gonadotropin, the hormone the young placenta makes once an embryo implants. It keeps your corpus luteum active so it keeps producing progesterone and the womb lining stays intact. A pregnancy test reacts to exactly this hormone. An hCG level is therefore a sign of pregnancy, not a measure of how it will go.
Your body starts making hCG around implantation, roughly six to ten days after ovulation. From that moment the level in your blood climbs quickly.
In the early weeks hCG usually doubles every two to three days in an ongoing pregnancy. Around eight to eleven weeks it peaks, then falls again and stays at a lower level for the rest of the pregnancy.
Because hCG rises so steeply early on, an early blood test can pick the hormone up before a urine test does. We cover that difference further down. To see how hCG fits alongside other values, visit our page on the hCG biomarker.
What are normal hCG values by week?
Normal hCG values form wide ranges, not fixed targets. The table below shows commonly used ranges by week of pregnancy, counted from the first day of your last period. Read them as a guide with a lot of margin, because healthy pregnancies can sit well above or below these numbers.
The figures in this table are a general guide. Every lab uses its own reference values, so always compare your result with the range printed on your own lab report.
| Week of pregnancy (from last period) | Commonly used hCG range (IU/L) |
|---|---|
| 3 weeks | 5 to 50 |
| 4 weeks | 5 to 426 |
| 5 weeks | 18 to 7,340 |
| 6 weeks | 1,080 to 56,500 |
| 7 to 8 weeks | 7,650 to 229,000 |
| 9 to 12 weeks | 25,700 to 288,000 |
| 13 to 16 weeks | 13,300 to 254,000 |
| 17 to 24 weeks | 4,060 to 165,400 |
Look at the overlap between the weeks. At five weeks a value of 18 can be just as normal as a value in the thousands. That is exactly why you should not compare your number with a friend's, and why your midwife would rather look at your trend than at one isolated reading.
A high or low value within these ranges says nothing on its own about how your pregnancy is going. Values differ widely between women, and even between different pregnancies in the same woman.
Why does the rise matter more than a single value?
The rise in hCG tells you more than a single reading, because starting values vary so much. That is why doctors usually test twice, 48 to 72 hours apart, and look at whether the value rises as expected. A healthy early pregnancy typically shows a doubling of roughly every two to three days.
Imagine two women who both have a first value of 100. For one it becomes 220 after two days, for the other 130. The same starting value, a very different pattern. The trend gives your midwife far more to go on than that single starting point.
Worth knowing: the doubling slows down as the value gets higher. Above about 6,000 IU/L a healthy pregnancy can take longer than 48 hours, and that is perfectly normal. A slower rise later in pregnancy therefore means something different from a slower rise at a low starting value.
If you want to compare two of your own results, you can do so with our hCG calculator. The tool works out your doubling time, so you walk into the conversation with your midwife better prepared. We explain step by step how to read that result in our article on hCG doubling time and how fast hCG should rise.
What can abnormal hCG values mean?
An hCG value that falls outside expectations can mean many different things and is not a diagnosis on its own. Only your midwife or GP can interpret a result, usually together with an ultrasound and your symptoms. Below we calmly set out what a higher or lower value could mean, without drawing conclusions about you.
Remember with everything below: these are possibilities, not statements about your situation. A number alone never tells the whole story.
A higher value than expected need not be a cause for worry. Often the pregnancy is simply further along than thought, for example because of an uncertain date for your last period. A high value can also fit a multiple pregnancy, because several placentas together make more hormone. In rare cases another cause is involved, which is exactly why an ultrasound is so helpful.
A lower or slowly rising value can mean the pregnancy is less far along than calculated. Sometimes a slower than expected pattern or a falling value points to a miscarriage or an ectopic pregnancy. Those are significant possibilities, and that is precisely why the assessment belongs with your doctor and not with a number on paper.
- Higher than expected: possibly further along, or a multiple pregnancy.
- Lower than expected: possibly less far along than calculated, or an early stage.
- Slowly rising or falling: a reason for your doctor to look further with follow-up and an ultrasound.
A falling hCG value after an earlier positive test is always something to discuss with your midwife or GP. What a fall means depends on your whole picture. We cover this with care in our article on hCG levels in a miscarriage and what the values show.
Blood test or urine test: what is the difference?
A blood test and a urine test both measure hCG, but in different ways. A urine test, the familiar pregnancy test from the chemist, gives a yes or no. A blood test measures the exact amount of hCG in IU/L and can usually pick the hormone up a few days earlier. To track a rise, you therefore need a blood test.
A urine test is ideal for confirming that you are pregnant. It is cheap, quick and can be done at home, and is positive in most women around the day of your expected period.
A blood test gives a number rather than a line. That lets you compare two readings and follow the trend, something a urine test cannot do. That makes the blood test valuable when your doctor wants to follow your hCG.
| Urine test | Blood test | |
|---|---|---|
| Result | Yes or no | Exact value in IU/L |
| Earliest reliable | Around expected period | A few days earlier |
| Track a trend | Not possible | Possible with repeat readings |
| Where | At home | At a sampling point |
If you want to go deeper into when each test is useful, read our article on a pregnancy test by blood or urine and the difference. You can do an hCG blood test without a referral through our pregnancy blood test.
When should you contact your midwife or GP?
Always contact your midwife or GP if you are worried, have questions about a result or experience symptoms. They can place your hCG value in the right context, together with an ultrasound and your story. A blood result is never meant for drawing your own conclusion.
Do not wait until you are certain. Doubt is already a good reason to call, that is what your care provider is for.
There are symptoms where you should not wait. With severe abdominal pain, shoulder pain or heavy bleeding, contact your GP, midwife or the out-of-hours service straight away. This can point to an ectopic pregnancy, which needs to be assessed quickly.
- Severe or persistent abdominal pain, often on one side.
- Shoulder pain, especially together with abdominal pain.
- Heavy or persistent bleeding.
- Dizziness or fainting.
For less urgent questions, such as a result you do not quite understand or mild symptoms, you are always welcome to get in touch. Reliable information is also available on Thuisarts.nl, but that does not replace personal advice from your own care provider.
If you do not yet have a midwife, your GP is the logical starting point. If you want to orient yourself more broadly on fertility and hormones, read our overview on fertility testing for women and which blood tests and hormones are involved.
Frequently asked questions
How fast should my hCG value double?
In the first weeks hCG usually doubles roughly every two to three days in an ongoing pregnancy. As the value gets higher, doubling slows down, which is normal. Your midwife assesses whether your rise fits your situation, because there is a lot of natural variation.
Can I tell from my hCG value whether it is twins?
A higher hCG value is more common in a multiple pregnancy, but you cannot use it to prove or rule out twins. The values overlap too much with those of a single pregnancy. Only an ultrasound gives certainty here, usually around the sixth to eighth week.
My hCG value is low, does that mean a miscarriage?
Not necessarily. A low value can also mean you are less far along than thought, for example because of an uncertain date. A single low value says little, it is the trend over a few days plus an ultrasound that your doctor looks at. Always discuss a low or falling result with your midwife or GP.
Can I track my hCG at home with a pregnancy test?
A home test gives a yes or no, not a number, so you cannot use it to follow a rise. To compare values you need a blood test that measures hCG in IU/L. If you have two blood results, you can work out the doubling time with our hCG calculator.
Sources
- NHG-Standaard Miskraam (Dutch College of General Practitioners, 2017).
- Thuisarts.nl, information on pregnancy, miscarriage and ectopic pregnancy (based on NHG guidelines).
- Williams Obstetrics, chapter on the placenta and hCG in early pregnancy (Cunningham et al., 2022).
- Dutch Society of Obstetrics and Gynaecology (NVOG), patient information on early pregnancy.
Every blood test result through Lunara includes a professional assessment by a BIG-registered doctor. Always discuss a pregnancy and your hCG levels with your midwife or GP.
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