Estimated Doubling Time and hCG Levels Chart
When you plan to become pregnant or feel that you may already be pregnant, you often reach for that home pregnancy testing kit that's commonly available in the market. The home kit uses a simple method to test whether you are or you aren't pregnant; it tests your urine sample.
If your urine contains traces of the hCG hormone, the result is positive. Similarly, if there are no traces of hCG, the result is negative. However, the test is not always fool-proof and may not give you a hundred percent accurate result, as your body may go through various hormonal shifts, leading to a wrong result. A better way to understand the entire hCG-based pregnancy testing concept is to know more about it.
Human chorionic gonadotropin, also known as hCG, is a hormone which is produced in your body at the time of pregnancy. The cells in the placenta help to produce the hormone. You will probably see the first traces of the hCG hormone in your urine when taking a urine test after at least 12 to 14 days of conception. If you take a blood test, you will be able to detect the traces of hCG after about 11 days of conception.
Here is a look at the normal range of hCG levels when you are pregnant:
|Pregnancy Week||Normal hCG levels at various weeks|
|3 weeks after LMP:||5 – 50 mIU/ml|
|4 weeks after LMP:||5 – 426 mIU/ml|
|5 weeks after LMP:||18 – 7,340 mIU/ml|
|6 weeks after LMP:||1,080 – 56,500 mIU/ml|
|7 – 8 weeks after LMP:||7, 650 – 229,000 mIU/ml|
|9 – 12 weeks after LMP:||25,700 – 288,000 mIU/ml|
|13 – 16 weeks after LMP:||13,300 – 254,000 mIU/ml|
|17 – 24 weeks after LMP:||4,060 – 165,400 mIU/ml|
|25 – 40 weeks after LMP:||3,640 – 117,000 mIU/ml|
The hCG levels normally increase by 66 to 100% in 48 hours (1).
Doubling time refers to the time it takes for the hCG levels to increase after the embryo implants in the uterus. Doubling time is important because an increasing hCG levels are a sign of healthy pregnancy.
If the hCG levels are less than 1,200 mIU/ml (mili International Unit / mililiter), they can double in 48-72 hours. And if the levels are between 1,200 and 6,000 mIU/ml, they double in 72-96 hours. The hCG levels hit their peak during the initial weeks of your pregnancy, between the 8th and 11th week. However, as you move further in your pregnancy and reach the final trimester, the hCG levels in your body start to decline.
To calculate your hCG levels, you will have to enter the data from two beta hCG samples. The calculator will check the doubling time between the two levels. You have to first enter the value of your first hCG test levels. Then enter value of the second hCG test levels. Mention the time gap between the two hCG tests. Then click on the ‘calculate’ button to get the results.
According to the researchers at the University of Pennsylvania School of Medicine, if you have a successful intrauterine pregnancy, the levels of hCG will increase by about 35% within 2 days.
In a majority of normal pregnancies, the hCG levels double in 48-72 hours, it means that they could possibly double twice in a week. As the levels increase and your pregnancy progresses, the doubling could take 96 hours.
However, if your hCG levels are increasing at a lower rate, do not panic. It could still be a healthy pregnancy.
There is no scientific and medical way through which you can safely and assuredly increase your hCG levels. There are some supplements available in the market but they are not regulated by the FDA. Do not try them as they could harm your pregnancy. If you are worried that your hCG levels are not in the normal range, speak to your doctor about your concerns and follow proper medical advice.
A bhCG test refers to a Beta Human Chorionic Gonadotropin test. While an hCG test is done through a urine sample, the bhCG test is performed on your blood sample. The bhCG test checks for a confirmed pregnancy and results will usually show as positive when you miss your first period. Your lab technician will take a small sample of blood from your vein to carry out the test.
Even though the hCG hormone is only associated with a positive pregnancy, it is possible that you have it in the system even when you are not pregnant. Here are some reasons why it could happen:
A biochemical pregnancy: One of the first reasons of positive hCG levels could be that you go through a biochemical pregnancy, which means that you do become pregnant, but you lose the fetus even before you realize that you are pregnant. The hCG levels take some time to leave your body, and when this happens you may still end up seeing it in your test results. Also, the results pick up the slightest amount of hCG levels.
Pituitary hCG: While hCG is produced by the placenta, sometimes, it is also produced by your pituitary gland in your brain. The pituitary gland secretes various hormones that help to control your endocrine organ systems (such as reproductive organs, thyroid, pancreas and more). The pituitary gland secretes three other hormones (the thyroid stimulating hormones, the luteinizing hormone and the follicle stimulating hormone), which are very similar to the hCG hormone. If your hCG is indeed secreted by the pituitary gland, the levels will not increase the way they do if you are pregnant.
Cancerous cells: In some cases, the hCG hormone is also produced if you have any cancerous cells in your body.
Interference from antibodies: It is possible that you have some antibodies in your blood that interfere in your hCG test and show a false presence or a false high count. However, it will only happen when you take the blood sample test.
If you notice that your hCG levels are dropping even if you do have a confirmed pregnancy, it could mean quite a few things. Firstly, it could mean that you possibly have irregular menstrual cycles, or your menstrual cycles are longer than most women.
Secondly, a drop in the levels of hCG could mean that you may have an ectopic pregnancy or a miscarriage. A study was conducted in which a pregnant woman had dropping levels of the hCG hormone, and even though her physician felt it was a case of miscarriage or a non-viable pregnancy, later tests revealed that she could go ahead with the pregnancy.
Most home pregnancy test kits detect and measure hCG levels in the urine, but don't display the exact hCG levels. Unless you are using a digital pregnancy test kit, which records the exact hCG levels in your urine, you cannot determine the hCG amounts through a home test.
Disclaimer: One of your first brushes with hCG will be when you take a home pregnancy test or get a blood test done to determine whether or not you are pregnant. Whatever your results, make sure you run them by your doctor to know exactly what's happening. It's possible that the hCG levels may sometimes also show a false reading, it is best to get it checked through your medical care professional.
Moms, did you take a urine test or blood test to check your pregnancy status? Did the results come out accurate or were you confused?
 Detection of early pregnancy forms of human chorionic gonadotropin by home pregnancy test devices.Butler SA, Khanlian SA, Cole LA.Clin Chem. 2001 Dec;47(12):2131-6.PMID:11719477
 1: Fritz MA, Guo SM. Doubling time of human chorionic gonadotropin (hCG) in early normal pregnancy: relationship to hCG concentration and gestational age. Fertil Steril. 1987 Apr;47(4):584-9. PubMed PMID: 2436952.
 Konrad G. First-trimester bleeding with falling HCG: Don’t assume miscarriage. Canadian Family Physician. 2007;53(5):831-832.