hCG in Blood: How Pregnancy Testing Works & Why Blood Tests Are More Accurate
Pregnancy tests are an essential tool for confirming pregnancy, and they work by detecting the hormone human chorionic gonadotropin (hCG). This hormone is produced by the placenta shortly after a fertilised egg implants in the uterus. While both urine and blood tests can detect hCG, blood tests are significantly more accurate. Let’s explore why.
What is hCG?
Human chorionic gonadotropin (hCG) is a hormone that plays a vital role in pregnancy. It is secreted by cells in the developing placenta and helps maintain the corpus luteum, which in turn supports progesterone production to sustain the pregnancy. hCG levels rise rapidly in early pregnancy, doubling approximately every 48–72 hours.
How Pregnancy Tests Work
Pregnancy tests, whether at-home urine tests or laboratory blood tests, work by detecting hCG. However, the method of detection and accuracy differ between the two types of tests.
Urine Pregnancy Tests
Urine pregnancy tests are the most commonly used home-based tests. They work by detecting hCG in urine through a chemical reaction that produces a visible indicator, such as a line or a digital readout.
- Pros: Convenient, affordable, and provide quick results.
- Cons: Less sensitive, may yield false negatives if taken too early or if urine is diluted.
Blood Pregnancy Tests
Blood pregnancy tests are performed normally in a medical setting and can detect much lower levels of hCG compared to urine tests. However, the NG Precision all in one pregnancy test can now be used at home. There are two types:
- Qualitative hCG Blood Test – This test simply confirms whether hCG is present or not, much like a urine test.
- Quantitative hCG Blood Test (Beta hCG Test) – This test measures the exact amount of hCG in the blood, allowing doctors to track pregnancy progression and detect potential complications.
Why Are Blood Tests More Accurate?
Blood tests provide greater accuracy for several reasons:
- Earlier Detection: Blood tests can detect hCG as early as 6–8 days after ovulation, whereas urine tests typically require higher levels of hCG and may not be reliable until after a missed period.
- Lower False Negative Rate: Since blood tests can detect smaller amounts of hCG, they are less likely to produce false negatives compared to urine tests.
- Monitoring Pregnancy Health: Quantitative hCG blood tests can help track the progression of pregnancy and identify potential issues such as ectopic pregnancy or miscarriage. (This is done within a medical setting)
Conclusion
While at-home urine pregnancy tests are convenient and widely used, blood tests offer a higher level of accuracy, earlier detection, and better monitoring of pregnancy progression. If you need confirmation or suspect a pregnancy but receive a negative urine test, a blood test can provide a definitive answer. The all in one at home blood pregnancy test can be used at any time and anywhere, you no longer need to wait for your morning urine.
