What are hCG Levels
hCG stands for human chorionic gonadotropin and is the pregnancy hormone. It is first produced by the cells that will form the placenta. hCG is the hormone detected by a pregnancy test which can normally be detected by a blood test around 10 days and through a urine test at about two weeks after conception. hCG levels refers to the increase in the amount of hormones as your pregnancy develops. Your hCG levels will double every 24 to 72 hours reaching their highest levels sometime towards the end of the first trimester.
Important points on hCG levels:
- A positive test for pregnancy is an hCG level abve 25mlU/ml.
- The hCG levels in the majority of pregnancies will doulbe every two to three days. As your pregnancy develops, the time it takes to double may increase to as much as every 96 hours.
- Low hCG levels may result in a normal healthy pregnancy; the most important part of increasing levels is whether or not they are doubling every two to three days.
- The hCG hormone is measured in milli-international units per milliliter (mIU/ml).
- A gestational sac may usually be seen through a transvaginal ultrasound once hCG levels have exceeded the 1,000 to 2,000mIU/ml mark.
- hCG levels should not be used for pregnancy dating because these numbers differ so much.
- There are two common types of hCG tests. A qualitative hCG test detects if hCG is present in the blood. A quantitative hCG test (or beta hCG) measures the amount of hCG actually present in the blood.
The range of hCG levels during pregnancy:
hCG levels in weeks from LMP (gestational age)* :
- 3 weeks LMP: 5 – 50 mIU/ml
- 4 weeks LMP: 5 – 426 mIU/ml
- 5 weeks LMP: 18 – 7,340 mIU/ml
- 6 weeks LMP: 1,080 – 56,500 mIU/ml
- 7 – 8 weeks LMP: 7, 650 – 229,000 mIU/ml
- 9 – 12 weeks LMP: 25,700 – 288,000 mIU/ml
- 13 – 16 weeks LMP: 13,300 – 254,000 mIU/ml
- 17 – 24 weeks LMP: 4,060 – 165,400 mIU/ml
- 25 – 40 weeks LMP: 3,640 – 117,000 mIU/ml
- Non-pregnant females: <5.0 mIU/ml
- Postmenopausal females: <9.5 mIU/ml
* These numbers are just a GUIDELINE– every woman’s level of hCG can rise differently. It is not necessarily the level that matters but rather the change in the level.
Low hCG levels:
It is important to know that low hCG levels can mean nothing and you may very well have a normal and healthy pregnancy. It is possible that a low hCG level can be a sign of a potential complication, but the most important question is whether the levels are doubling every two to three days. Low hCG levels could be related to one of the following:
- Miscalculation of pregnancy dating
- Possible miscarriage or blighted ovum
- Ectopic pregnancy
High hCG levels:
Similarly, high hCG levels may result in a normal and healthy pregnancy. Just like low hCG levels, an initial high level test should be rechecked within two to three days to monitor doubling levels. A high hCG level may be related to one of the following:
- Miscalculation of pregnancy dating
- Molar pregnancy
- Multiple pregnancy
Schedule or hCG level testing:
The schedule of hCG testing from your healthcare provider may vary to others. This is normal because some providers will test for different reasons. It is not unusual for a healthcare provider avoid routinely checking you hCG levels unless there are any symptoms suggesting a potential problem. Previous problems such as a history of miscarriage may lead to additional testing to monitor the health and wellness of your baby.
hCG levels following a pregnancy loss:
hCG levels will usually return to pre-pregnancy levels within six weeks following the loss. Your healthcare provider will monitor you hCG levels to make sure your body is returning to normal. The presence of higher levels of hormones at the time of the loss may take a little longer to leave your body. You healthcare provider may recommend a D&C if your levels are not declining appropriately. Your healthcare provider will be monitoring s usually will continue to test hCG levels after a pregnancy loss to ensure they return back to <5.0
Factors affecting hCG levels:
The only thing that should change your hCG levels would be taking medications that contained hCG. In most cases, these medicines will be involved with fertility treatments and your provider would be informing you on the potential ways this would affect testing. There are no other medications that affect your levels of hormones.