Beta-hCG (Pregnancy Hormone)

What is beta-hCG?

Human chorionic gonadotropin (hCG) is a hormone produced, shortly after the fertilized egg implants in the uterine wall, by the cells that will go on to form the placenta. In the first weeks of pregnancy, it supports the corpus luteum in the ovary and keeps progesterone production going. Because the beta-hCG test targets the hormone's unique beta subunit, it gives a sensitive result that is specific to pregnancy.

The blood test reports the amount of hormone as a number and can also detect low levels that home urine tests cannot pick up. The measurement is performed on serum using immunological methods, and the result is given in mIU/mL. The numerical value makes it possible to monitor the course of a pregnancy with serial measurements. The hormone reaches its highest level within the first three months, then decreases somewhat and follows a more stable course.

When is the beta-hCG test ordered?

This test is most often ordered to confirm pregnancy, but it is also an important tool for assessing whether a pregnancy is progressing healthily. Because the hormone level is expected to rise steadily in the early weeks, your doctor may order two measurements 48 hours apart. The results are especially helpful in the first weeks, when the pregnancy cannot yet be seen on ultrasound. Less commonly, it is also a marker used in the diagnosis and follow-up of certain tumors.

• A missed period or suspected pregnancy
• Confirming pregnancy after IVF or insemination treatment
• Bleeding, lower abdominal pain or suspected ectopic pregnancy in early pregnancy
• Monitoring the decline in hormone levels after a miscarriage
• Ruling out pregnancy before an X-ray, certain drug treatments or surgery
• Follow-up of molar pregnancy or certain testicular and ovarian tumors

How do you prepare for the beta-hCG test?

You do not need to fast for beta-hCG, and blood can be drawn at any time of day; unlike urine tests, there is no need to wait for the early morning. The blood test can detect pregnancy earlier than a urine test, but the most reliable result is still obtained after a missed period. If a test done very early is negative and pregnancy is still suspected, it can be repeated a few days later. You do not need to restrict your fluid intake for the blood test; drinking water does not affect the result.

Fertility treatment injections that contain hCG can cause a false-positive result in the days following the injection, so tell your doctor the date of the injection. High-dose biotin supplements can also affect some measurement methods. Blood is drawn from a vein in the arm with sterile equipment; a Curavita nurse collects the sample at your home or workplace and delivers it to the laboratory.

What does the beta-hCG result mean?

A result below the reference value generally indicates that you are not pregnant; however, if the test was done very early, the hormone may not yet have reached a measurable level. An elevated value most often points to pregnancy. Whether the pregnancy is progressing healthily, however, is not determined by a single measurement but by the rate of increase across serial results, together with ultrasound findings. When the gestational sac will become visible on ultrasound is also largely predicted from the level of this hormone.

Values that rise more slowly than expected or that fall may require close monitoring for miscarriage or ectopic pregnancy; levels much higher than expected may be associated with a multiple pregnancy or, rarely, a molar pregnancy. Mild elevations originating from the pituitary gland may also be seen in postmenopausal women. Because expected levels vary by laboratory, age, sex and week of pregnancy, this page shows the reference values of the laboratory that performs the test. Your result should be evaluated by your doctor together with your symptoms, ultrasound and other tests.