How to Measure and Interpret Blood HCG Levels to Assess a Pregnancy

Becoming a mother is a very special part a woman’s life. Usually, the absence of a normal menstrual cycle is one of the first signs of pregnancy but the symptoms may vary from one woman to another, depending on several factors. That is why it is important that one should consider undergoing a test like the beta HCG test to confirm the diagnosis. A pregnancy can be confirmed using the beta HCG test as the test looks for the presence of the human chorionic gonadotropin (HCG) hormone in the woman’s blood, and provides highly accurate results.

Apart from a pregnancy blood test, urine pregnancy tests are also quite popular today. However, regardless of whether it is a blood test or a urine test, both are used to detect HCG hormones for a conformed diagnosis. Throughout a pregnancy, the beta HCG levels tend to change by the day.

What is HCG?

The beta HCG test gets its name from the components it detects, where beta refers to the beta protein that is found in the HCG hormone.

HCG or the Human Chorionic Gonadotropin hormone is produced by the cells that line the embryo in the initial stages of pregnancy and later, it is produced by the cells of the placenta to provide nourishment to the growing foetus. While the HCG levels may fluctuate throughout a pregnancy, the beta HCG hormone can be detected with a blood test 10-11 days after conception. In the beginning of the pregnancy, the HCG levels tend to almost double every 72-90 hours, reaching their peak sometime during the 8th-10th weeks of pregnancy.

Types of Beta HCG Tests

Detecting the presence of the HCG hormone in the blood, this testImagecan be categorised into two types:

  • The Qualitative Beta HCG Blood Test: The qualitative test is performed to find out if the HCG hormone is being produced in one’s body. It provides a simple yes or no result as to whether a woman is pregnant or not. This test can be used to confirm a pregnancy as early as 10 days after conception.
  • The Quantitative Beta HCG Blood Test: This test measures the exact levels of HCG in the blood. Providing highly accurate results, the test can also be used to measure very low levels of HCG in the blood. Apart from detecting a pregnancy, this test can also provide important information about the pregnancy, like the exact age of the foetus, etc. The quantitative test can also help diagnose abnormalities, like ectopic pregnancies, molar pregnancies, or the possibility of miscarriages.

When is a Beta HCG Test (Serum) Prescribed?

Generally, a qualitative beta HCG test is prescribed initially to screen for a pregnancy. On the Other hand, the quantitative test may be prescribed several times during the pregnancy to monitor the progression of the pregnancy, screen the foetus, or even assess its age in the early stages of pregnancy.

Other reasons why a doctor may prescribe the beta HCG blood test include:

  • To rule out an ectopic pregnancy (when a fertilised egg implants outside of the uterus)
  • For prenatal Down Syndrome screening
  • To Monitor a pregnancy with higher risks of miscarriage
  • Diagnosis of pregnancy-related tumours
  • To check the effectiveness of a fertility treatment
  • To diagnose ovarian cancer


Generally, a person may have trace amounts of HCG in their blood. However, if they are not pregnant, their HCG levels should be less than 5 mlU/ml. On the other hand, if one is pregnant, their HCG levels will vary, depending on in the progression of the pregnancy.

On average, the normal range of HCG levels, based on the different weeks of pregnancy should be as follows:

  • 3 Weeks: 5-50 mIU/ml
  • 4 Weeks: 5-426 mIU/ml
  • 5 Weeks: 18-7.340 mIU/ml
  • 6 Weeks: 1.080 to 56.500 mlU/ml
  • 7 to 8 Weeks: 7.650 to 229.000 mlU/ml
  • 9 to 12 Weeks: 25.700 to 288.000 mlU/ml

However, it is important to understand that the above-mentioned values are not hard and fast. An individual’s HCG levels may vary, depending on certain factors like the average length of their menstrual cycle, age, medical conditions, etc. As the beta HCG lab test may be prescribed for various reasons, and as the results may vary from case to case, it is best to consult a doctor with the reports for a proper diagnosis. They will be able to interpret the test results and make relevant suggestions for the same.

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