The beta hCG test is commonly used to confirm pregnancy. Learn how to interpret the results of this test.
When it comes to confirming pregnancy, the medical professionals at Fertility Answers rely on the beta hCG test as an initial predictor of a healthy pregnancy. This blood test detects the important pregnancy hormone called human chorionic gonadotropin, or hCG. This hormone is produced by the placenta after fertilization occurs and is the first hormonal message from the placenta to the mother. HCG production peaks somewhere between 8 and 11 weeks of pregnancy and then levels off for the remainder of the pregnancy. It is this early hCG increase that can sometimes give you the feelings of ‘morning sickness’.
Urine pregnancy tests versus blood serum hCG tests
Over-the-counter pregnancy tests, generally available at your local pharmacy, can detect the presence of the hormone hCG in your urine. An OTC test can often provide a quick and convenient indication of if you are pregnant. However, keep in mind that false negatives are common with OTC urine pregnancy tests, meaning they are not as accurate as a blood test.
At Fertility Answers, we rely on the beta hCG test performed in our labs to give us a measurement of the hCG hormone in your blood sample. It is typically conducted about 11 to 14 days after conception or around the time you would expect your menstrual period. If you have had an insemination or an embryo transfer, we will typically schedule this test about 2 weeks after the procedure. The test is highly sensitive and can detect even low levels of hCG, making it an effective tool for confirming pregnancy.
The beta hCG test conducted here at Fertility Answers is a quantitative serum blood test, which means it measures the exact level of hCG in the blood. Serum beta hCG is proportional to the number and activity of the trophoblastic cells in the growing embryo. Therefore, higher serum beta hCG levels are associated with pregnancy outcomes and IVF success. These measurements can be useful for monitoring the progression of pregnancy or assessing potential complications.
Interpreting baseline beta hCG test results
Interpreting your baseline beta hCG test results involve assessing the level of the hormone in relation to the stage of pregnancy. It’s important to keep in mind that these levels can vary widely from person to person, and a single measurement may not provide a complete picture. Understanding the results of your first beta hCG test can be confusing for a non-medical person, so let’s explore how to interpret these results more accurately:
- In general, a baseline beta hCG of <5 mIU/mL taken approximately 12-14 days from expected conception is considered negative for pregnancy.
- Baseline beta hCG >25 mIU/mL taken approximately 12-14 days from expected conception 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 general, a baseline beta hCG level >100 mIU/mL is generally considered a good, positive result.
- A really high beta hCG could indicate multiples (twins or triplets), which would be confirmed through an ultrasound.
Tracking hCG over time provides a more accurate picture
After your initial baseline quantitative hCG test we will schedule you for a second test a few days later. This is because what’s more important than the absolute beta hCG number is how it trends over time. Generally, hCG levels in a healthy pregnancy should double every 48 to 72 hours during the early days as an indication that the embryo has implanted and is growing. The higher the percentage of rise in hCG following the baseline, the better the chances for success.
Deviations from an expected rising pattern may indicate miscarriage, ectopic, or other issues, requiring further evaluation by a healthcare professional. In the event of a miscarriage, hCG levels typically decrease from previous measurements. For example, a baseline hCG level of 120 mIU/mL that’s dropped to 80 mIU/mL two days later can indicate the embryo is no longer developing and the body isn’t producing more hormones to support its growth.
Tracking beta hCG numbers may also alert your care team to a possible ectopic pregnancy, a condition where the embryo implants outside the uterus, usually in one of the fallopian tubes. In the case of an ectopic, hCG levels may rise. But a rule of thumb is that if it rises less than 66% over 48 hours when hCG is below 1,200 mIU/mL means it is likely, but not a certainty, that the pregnancy is ectopic. An ectopic pregnancy is always confirmed via an ultrasound.
The bottom line on interpreting hCG test results
The bottom line is that beta hCG testing is just one data point we use to confirm a pregnancy. While a positive result generally indicates pregnancy, the level of hCG alone is not sufficient to determine the viability of the pregnancy or potential complications. Better predictors of pregnancy outcomes are the trends in hCG levels over time and ultrasound findings. Therefore, don’t be overly alarmed by a low initial baseline beta score. Many normal, healthy pregnancies start out with a low beta hCG and may mean the embryo just has a slower implantation process.
If you have concerns about your beta hCG numbers, don’t be afraid to ask us about your chances of success given the information at hand.