Human chorionic gonadotropin, more frequently referred to as hCG, is a hormone that is produced during pregnancy by the placenta. The hCG hormone is created by the cells that form the placenta and the first traces can be found as early as eleven days after conception (3-4 days after implantation) by a blood test. A urine test takes slightly longer to detect the hormone and is not effective until twelve to fourteen days after conception.
How Does hCG Increase?
In most normal pregnancies at levels below 1,200 mIU/ml the hCG level usually doubles every 48-72 hours and it normally increaseses by at least 60% every two days. As your pregnancy develops the increase slows down. After two to three months the increase will slow even further and eventually decline before reaching a plateau for the duration of the pregnancy. Between 1,200 and 6,000 mIU/ml serum, the hCG usually takes 72-96 hours to double, and above 6,000 mIU/ml, the hCG often takes over four or more days to double. It makes little sense to follow the hCG values above 6,000 mIU/ml as at this point the increase is normally slower and not related to how well the pregnancy is doing.
How Do You Know What Your Levels Are?
There are two tests that are able to provide information about your hCG levels. The first is a qualitative test. This test simply checks for the presence of hCG in the blood. The second option is a quantitative test. This test measures exactly how much of the hormone is present.
What Levels are Normal?
What is normal for hCG levels depends primarily on the stage of the pregnancy but can also vary based on the person. Because of the possibility of differences one should not completely base the health of the pregnancy on these numbers. It is possible to have a normal pregnancy and healthy baby with very low numbers. Still, there are numbers that are generally associated with certain stages of a pregnancy. If you are not pregnant your hCG levels should be less than 5mIU/ml. If you are pregnant the number should be above 25mIU/ml. Typically an ultrasound will not be able to pick up anything until the levels have reached at least 2,000mIU/ml, this usually occurs somewhere between weeks five and eight.
Medications and hCG Levels
When it comes to a normal hCG level the only medications that can affect hCG are medications containing hCG. The most common medication affecting hCG are infertility treatments. Infertility drugs will increase the body’s natural hCG levels and thus increase the chance of pregnancy.
The blood testing given to a pregnant woman in the beginning stages of prenatal care will often include an hCG test. This test will show larger than normal amounts of hCG if the woman is pregnant with multiples. The more fetuses developing in-utero, the more hCG that will be present in the blood stream.
It is widely thought that hCG levels are a predictor of how far along a pregnancy is in terms of weeks. A more accurate measure of fetal development will occur when the first ultrasound is given. Ultrasounds are a far better predictor of pregnancy stage than hCG levels.