Hcg levels in early pregnancy are what pregnancy tests look for. Pregnancy tests will show a positive result if hcg is detected. This pregnancy hormone stands for "human chorionic gonadotropin", and is measured in milli-international units per milliliter (mIU/ml).

When is This Hormone Detected?

Hcg levels in early pregnancy can first be detected about 11 days after conception by a blood test, and about 12 - 14 days after conception by a urine test . Generally, the hcg levels in early pregnancy will double every 36-72 hours in early pregnancy. This rate will increase to every 96 hours after a few weeks.

The rate at which these levels double will reach its peak in the first 8 - 11 weeks of pregnancy, and then will decline and level off for the remainder of the pregnancy. After about the 12th week of pregnancy , the placenta will take over.

A negative pregnancy test result occurs with levels of hcg less than 5mIU/ml. Anything above 25mIU/ml will usually yield a positive result.

It's the Rate of Increase That Matters Most - Not the Numbers

Don't read too much into the actual hcg number. It's the rate at which these numbers double that is more important.

A normal pregnancy may have low hcg levels in early pregnancy and result in a perfectly healthy baby. The results from an ultrasound are much more accurate than using hCG numbers.

HCG Levels Chart

The following chart is a general idea of the level of hcg at various points in early pregnancy:

3 weeks: 5 - 50 mIU/ml

4 weeks: 5 - 426 mIU/ml

5 weeks: 18 - 7,340 mIU/ml

6 weeks: 1,080 - 56,500 mIU/ml

7 - 8 weeks: 7, 650 - 229,000 mIU/ml

9 - 12 weeks: 25,700 - 288,000 mIU/ml

13 - 16 weeks: 13,300 - 254,000 mIU/ml

17 - 24 weeks: 4,060 - 165,400 mIU/ml

25 - 40 weeks: 3,640 - 117,000 mIU/ml

Non-pregnant females: <5.0 mIU/ml

Postmenopausal females: <9.5 mIU/ml

There is great variation in levels of hcg in early pregnancy. It isn't the actual number that matters in these results, but rather the change in values.

As stated before, doubling of these numbers should take place every 36-72 hours. A quantitative hcg test measures the amount of hcg present in the blood. To see if these numbers are doubling at a proper rate, your health care practitioner may administer blood tests every 36-72 hours if he or she feels that your pregnancy may be at risk.

A qualitative hcg test simply detects if hcg is present in the blood (such as a urine pregnancy test you can get from a drug store).

What Do Low Or High Levels Mean?

If these numbers are not doubling at the above stated rate, or are leveling off, this could signify miscarriage , or blighted ovum (fertilized egg attached to the uterine wall, but the embryo does not develop - the pregnancy sac develops, but not the embryo). This could also signify possible symptoms of ectopic pregnancy (when the fertilized egg attaches in a place other than inside the uterus - usually a fallopian tube).

If you are experiencing an unusually high value in hcg numbers, this could signify a molar pregnancy (the result of a genetic error during fertilization leading to growth of abnormal tissue within the uterus - these pregnancies rarely result a developing embryo), or multiple pregnancy.

HCG After Miscarriage or Childbirth

Most women return to a non-pregnant hcg range approximately 4 - 6 weeks after a miscarriage or delivery of a healthy baby. This can vary according to the circumstances (ie. spontaneous miscarriage, D & C, abortion or natural delivery). This also depends on how high the levels were at the time. The further along the pregnancy was, the longer it will take for levels to drop below <5.0 (non-pregnancy level).

In a miscarriage situation, sometimes a D & C (Dilation and Curettage) will be required if the miscarriage is not complete. This is a surgical procedure in which the uterus is emptied of it's pregnancy-related contents - such as parts of the placenta.