Human Chorionic Gonadotropin hCG, beta hCG (β-hCG, BHCG) Blood Test

Quantitative hCG testing, often called beta hCG (β-hCG), measures the amount of hCG present in the blood. It may be used to confirm a pregnancy. It also helps to diagnose an ectopic pregnancy, along with a progesterone test. An ectopic pregnancy is likely if there are no signs of an embryo or fetus in the uterus as expected, but hCG levels are elevated or rising.

An hCG level of less than 5 mIU/mL is considered negative for pregnancy, and anything above 25 mIU/mL is considered positive for pregnancy.

An hCG level between 6 and 24 mIU/mL is considered a grey area, and you'll likely need to be retested to see if your levels rise to confirm a pregnancy.

In a normal pregnancy, the β-HCG level doubles every 48-72 hours until it reaches 10,000-20,000mIU/mL. In ectopic pregnancies, β-HCG levels usually increase less. Mean serum β-HCG levels are lower in ectopic pregnancies than in healthy pregnancies. No single serum β-HCG level is diagnostic of an ectopic pregnancy.

In fact, abdominal ultrasound in conjunction with a β-hCG level of greater than 6,500 mIU per mL suggests the presence of an ectopic pregnancy.