Unveiling the Mysteries of hCG

by Pregnancy.org Staff

What Is HCG

calling for resultsIf you are like most women, even the mere thought of "Am I or am I not pregnant" can be a period filled with anxiety and/or excitement as you await a clear answer either way. Detective hats in place, we have tracked down and unmasked the one that can give you a definitive response -- a hormone called human chorionic gonadotropin; more commonly referred to as hCG. This hormone is made by cells that help form the placenta. It is present at each and every pregnancy, with production beginning as soon as the fertilized egg attaches to the uterine walls.

How Soon Can I Know If I'm Pregnant?

If you are in a hurry to learn that life changing "yes" or "no," you will need to opt for a blood test. hCG can be measured within a normal blood sample approximately 11 days after conception. Those a few days further along can have their hCG detected within a urine sample. The latter is what the majority of home pregnancy tests measure.

Your pregnancy test isn't positive yet? Don't worry! Some women don't produce enough hCG to trip a pregnancy test until two weeks after they've missed a period.

In general the hCG level will double every 48 to 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.

What About Those Numbers

The table below shows typical hCG values during pregnancy. These numbers are merely guidelines. Every woman's hCG levels may rise differently. It is not necessarily the level that matters but rather the amount of hCG increases during early pregnancy.

HCG Levels by Week
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 650-229,000 mIU/ml
9-12 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 <9.5mIU/ml

My hCG Levels Are Low

Don't panic just yet. Certainly a lower result bears watching. There are a number of different possibilities in play. A low hCG level could mean you have irregular cycles or longer cycles than average or you could ovulate later in your cycle. Your baby is really younger than the 28-day pregnancy wheel predicts. Unfortunately, for some, low levels could indicate an ectopic pregnancy or a possible miscarriage. Finally, there is also the chance you might be one of those women with a perfectly healthy pregnancy and lower hCG levels as your "norm." The only way to know for sure is to test again within a few days and compare the results to obtain a clearer picture on what may be happening with your baby and body.

My High hCG Levels Are High

Ah, this result could be exciting! A higher level of hCG might mean your baby is a little older than predicted. Maybe you ovulated earlier than you thought, or maybe that "strange cycle" was actually implantation taking place. Then there are those odds that you could be having twins! One negative option is a high level could possibly indicate a molar pregnancy, but know that is rare. You might simply be one of those women with a perfectly healthy pregnancy and higher hCG levels as standard for your body. Again, to help definitively know what is going on, you can have these checked again and evaluate the difference.