The Pregnancy Hormone hCG

hCG stands for human chorionic gonadotropin. hCG is a hormone produced during pregnancy. Pregnancy testing involves the detection of hCG.

The hormone hCG may also be used as a fertility drug to help follicles mature and to trigger ovulation.

Beta hCG, also known as quantitative serum beta-HCG, refers to the testing of the amount of hCG hormone present in the blood.

Your doctor may order a beta hCG if a urine test came back positive, or, if you're in the middle of fertility treatments, just before or when your period is due.

hCG is measured in milli-international units per milliliter. This is abbreviated as mIU/ml.

Repeat blood tests for hCG may be performed every two to three days to evaluate how quickly levels are rising. Slow-to-rise hCG levels may indicate a high risk for miscarriage.

The levels should double every 48 to 72 hours.

Whether you have high or low levels is not the best indicator of a healthy pregnancy. The more important thing to watch for is whether they are doubling as expected.

Here are the general ranges of hCG levels during pregnancy. They are just a guideline, every pregnancy is different. Ask your doctor if you're concerned about your hCG levels.

(The number of weeks listed is from your last menstrual period.)

• A level less than 5.0 mIU/ml is considered to be a negative pregnancy test.
• 3 Weeks: 5 to 50 mIU/ml
• 4 Weeks: 5 to 426 mIU/ml
• 5 Weeks: 18 to 7,340 mIU/ml
• 6 Weeks: 1,080 to 56,500 mIU/ml
• 7 to 8 Weeks: 7,650 to 229,000 mIU/ml
• 9 to 12 Weeks: 25,700 to 288,000 mIU/ml
• 13 to 16 Weeks: 13,300 to 254,000 mIU/ml
• 17 to 24 Weeks: 4,060 to 165,400 mIU/ml
• 25 to 40 Weeks: 3,640 to 117,000 mIU/ml

Wondering why the normal hCG range goes down mid-pregnancy? hCG levels peak around 8 to 11 weeks, and then decrease and level off for the rest of the pregnancy.

hCG may also be used during fertility treatment. Pregnancy hormone acts similarly in the body to the hormone LH. LH is the hormone that peaks just before ovulation and is key to triggering the last stage of follicle development.

A single injection of hCG—sometimes referred to as a trigger shot—may be given in the middle of a fertility treatment cycle. In a cycle with Clomid, gonadotropins, or IUI, the trigger shot may be given to boost ovulation and trigger release of the egg.

In an IVF treatment cycle, the trigger shot is given to push the follicles into the final stages of maturity. Then, your doctor will schedule an egg retrieval to removed the mature eggs from the follicles.