The human chorionic gonadotropin is also known as hCG. It is a hormone produced by the body during pregnancy. It is made by the cells that form the placenta. Levels of this hormone can be detected by a blood test in about 11 days after conception and about 12 -14 days by a urine test. The level of this hormone usually doubles every 72 hours. It will reach its peak in the first 8 – 11 weeks of pregnancy and will decline and level off for the remainder of the pregnancy. Doctors do not routinely check the level of hCG unless you are showing signs of a possible problem. Your health care provider will check your levels if you are bleeding, experiencing severe cramping or have a history of miscarriage.

Guideline to hCG level 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

This is just a guideline and can be different for every woman. It is not necessarily the level that matters but the change in level.

Source : American Pregnancy Association

What does a low level of hCG mean ?

Low levels of hCG could mean a lot of things. It should be recalculated with 48-72 hours to see how the numbers are changing. Low levels could mean the following :

• pregnancy dating misculation
• ectopic pregnancy
• blighted ovum
• possible miscarriage

What does high levels of hCG mean ?

High levels of hCG could mean a lot of things. It should be recalculated with 48-72 hours to see how the numbers are changing. High  levels could mean the following :

• pregnancy dating miscalculation
• molar pregnancy
• multiple pregnancy

What happens to my hCG level after a pregnancy loss ?

Most women expect their hCG levels to return to its original level 4-6 weeks after a pregnancy loss. This however depends on how the pregnancy loss occurred ( spontaneous miscarriage, abortion, D&C procedure or natural delivery) and how high the level was at the time of loss. Health care professional usually monitor your hCG levels after a pregnancy loss to make sure they return to normal to <5.0.

Does anything have an effect on hCG levels ?

A positive test usually indicates that you are pregnant. False positives are rare. However certain medical conditions such as certain cancers and miscarriage can give a false positive result. Some antibiotics may also alter the test.

Medications such as those used for fertility treatments may also affect the level. Other medications such as pain reliever, contraceptives and other hormone medications should not have any effect on the test that measures hCG level.

NOTE
An hCG level of less than 5mIU/ml is considered negative for pregnancy and above 25mIU/ml is considered positive for pregnancy.