Human Chorionic Gonadotropin hCG

The hormone, human chorionic gonadotropin (better known as hCG), is produced during pregnancy. It is made by cells that form the placenta, which nourishes the egg after it has been fertilized and becomes attached to the uterine wall. hCG can first be detected by a normal blood test about 11 days after conception and about 12 - 14 days by a urine test. In general the hCG level will double every 72 hours. The levels will reach their peak in the 8 - 11 weeks of pregnancy (the third month) and then will decline and level off for the remainder of the pregnancy.

3.5 weeks since LMP or 10 DPO (10 - 50 mIU's of hCG)

4 weeks since LMP or 13 DPO (25 - 100 mIU's of hCG)

4.5 weeks since LMP or 16 DPO (40 - 200 mIU's of hCG)

5 weeks since LMP or 19 DPO (80 - 400 mIU's of hCG)

5.5 weeks since LMP or 22 DPO (160 - 800 mIU's of hCG)

6 weeks since LMP ( 1,080 - 56,500 mIU/ml )

7 - 8 weeks since LMP ( 7, 650 - 229,000 mIU/ml )

9 - 12 weeks since LMP ( 25,700 - 288,000 mIU/ml )

13 - 16 weeks since LMP ( 13,300 - 254,000 mIU/ml )

17 - 24 weeks since LMP( 4,060 - 165,400 mIU/ml )

25 - 40 weeks since LMP( 3,640 - 117,000 mIU/ml )

Non-pregnant females: less than 5.0 mIU/ml
Postmenopausal: less than 9.5 mIU/ml

Key things to remember about hCG levels

About 85% of normal pregnancies will have the hCG level double every 48 - 72 hours. As you get further along into pregnancy and the hCG level gets higher, the time it takes to double can increase to about every 96 hours.

Caution must be used in making too much of hCG numbers. A normal pregnancy may have low hCG levels and deliver a perfectly healthy baby. The results on an ultrasound after 5 - 6 weeks gestation are much more accurate than using hCG numbers.

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

hCG is measured in milli-international units per millimeter (mIU/ml)

A transvaginal ultrasound should be able to see at least a gestational sac once the hCG levels have reached between 1,000 - 2,000mIU/ml. Because levels can differentiate so much and conception dating can be wrong, a diagnosis should not be made by ultrasound findings until the level has reached at least 2,000.

A single hCG reading is not enough information for most diagnosis. When there is a question regarding the health of the pregnancy, multiple testings of hCG done a couple days apart give a more accurate look at accessing the situation.

hCG levels should not be used to date a pregnancy since these numbers can vary so widely.

It is not common for doctors to normally re-check your hCG levels unless you are showing signs of a possible problem. A health care provider may re-check your levels if you are bleeding, having severe cramping or have a history of miscarriage.