HCG blood test

Making sense of the hCG blood test

The HCG blood test is one of the easiest medical tests to interpret. This is because it is a very special molecule, which is produced only by the placenta during pregnancy, for all practical purposes. (Very rarely, it can be produced by certain tumors, but these are so uncommon that we can safely ignore them). What this means is that the presence of hCG in the blood (or in the urine) means that the patient is pregnant. Of course, it doesn't tell us anything about the health of the pregnancy, or its location.

The major problem with interpreting the hCG result is that most people think negative means zero . They conclude that if the level is 7, this means that it is positive and they are pregnant. Unfortunately, this is not true , and a negative hCG is any level of less than 10 mIU/ml. This means that if the level is less than 10 mIU/ml, we can conclude that the patient is not pregnant.

However, a lot of women get confused by their results ( and sometimes doctors and the labs as well) add to this confusion by saying – Hey, look, your level is 11 , which means it’s a positive result and you are pregnant ! If you are confused, remember that hCG levels should not be seen in isolation. While one figure does give valuable information , serial HCG levels are far more useful, because the levels will keep on rising and doubling every 48 to 72 hours in a healthy pregnancy.