How Early Can a Qualitative hCG Test Detect Pregnancy?


In the days and weeks following the implantation of an embryo in the uterus, the cells that eventually form the placenta in a pregnant woman produce a hormone known as human chorionic gonadotropin (hCG). Usually, the results of hCG qualitative tests can show whether pregnancy has occurred or not. 

While women can choose to do at-home pregnancy tests, blood tests are generally more sensitive than home pregnancy tests. Qualitative hCG blood tests can help women seeking to get pregnant to know early enough if they have successfully conceived. The test can also reveal if an unintended pregnancy has occurred.

This article highlights the basic concepts around qualitative hCG blood tests and explains the accuracy of the tests. It also explains the difference between the two types of hCG tests and how they relate to pregnancy. 

Qualitative hCG Pregnancy Detection Period

In normal situations, hCG in the blood and urine of non-pregnant women is very low. A woman with an hCG level below 5 mIU/ml is considered not pregnant. Pregnancy hormone levels above 25 mIU/ml is a positive sign of pregnancy.

Qualitative hCG tests can detect elevated levels of the pregnancy hormone. But the hCG levels in blood and urine do not shoot up immediately when a woman becomes pregnant. Therefore, a test performed too early might produce an inaccurate result. 

However, the pregnancy hormone can be detected as early as 8 days after conception, and the level increases rapidly during the early stages of pregnancy. Usually, healthcare professionals conduct qualitative hCG blood tests, so results typically take longer than a home pregnancy test.

Ideally, a doctor will provide a blood test when a woman has missed her period. Implantation often occurs between 6 to 12 days after ovulation, and when that happens, hCG levels begin to rise. Therefore, qualitative hCG tests performed a little longer after a missed period are more likely to be accurate. 

Besides revealing unintended pregnancy or confirming a successful pregnancy, early pregnancy detection is essential for protecting the developing baby. Some medical treatments such as X-rays can potentially harm the embryo, making it important to screen women of child-bearing age before undergoing such treatments.

Doctors or healthcare professionals can provide adequate protection for the developing fetus if early pregnancy is detected through hCG qualitative tests. 

Qualitative and Quantitative hCG: What’s the Difference?

A blood pregnancy test is either a qualitative or a quantitative hCG test. While both tests are used to diagnose pregnancy, they don’t work exactly the same.

Doctors run a qualitative hCG test to confirm the presence of the hormone in the blood. Similar to a home urine test, the result of a qualitative hCG blood test only shows whether a woman is pregnant or not. The test is also about as accurate as a home urine test.  

On the other hand, a beta hCG test, also known as a quantitative hCG test, measures the exact level of the pregnancy hormone in the blood. The result of this test is usually very accurate as it can detect the slightest amounts of hCG in the blood. A quantitative test can help doctors to determine whether a pregnancy is developing normally or not. In general, hCG levels will go up steadily in the first trimester and start a gradual decline during the second and third trimesters.

Quantitative hCG tests can also help diagnose potential miscarriages, ectopic pregnancy, and screen for Down syndrome.

Accuracy of Qualitative hCG Blood Test 

An hCG qualitative test is accurate, but as with every other test, it is not always accurate a hundred percent of the time. 

In general, if the hCG qualitative result is negative, it means pregnancy has not occurred. But, as stated earlier, a qualitative hCG blood test performed too early might not detect pregnancy. If that is the case, the test will generate a false negative. 

To clear up doubts, it might be best to repeat the test within 2 to 3 days since hCG levels tend to change rapidly during early pregnancy. 

On the other hand, a false positive can, even in women who are not pregnant, although false-positive results are rare compared to false negatives. 

The reason for this is simple: certain medications can interfere with hCG levels in the blood. For example, fertility drugs, especially those that contain hCG, can get in the way of qualitative hCG tests and produce inaccurate results. 

Although not common, some women can have high hCG levels without being pregnant. Abnormally high pregnancy hormones in non-pregnant women can happen for a couple of reasons, including:

  • The occurrence of a molar pregnancy. A molar pregnancy is a non-cancerous mass inside the uterus that results from a pregnancy that implants but did not grow.
  • Recent miscarriage.
  • The unusual presence of antibodies in the blood.
  • Pituitary gland or other endocrine disorders
  • Cancer.

What is Urine hCG Qualitative?

The pregnancy hormone (hCG) is not only present in the blood but is also found in the urine of pregnant women. Urine hCG qualitative tests are similar to hCG qualitative blood test, except that it does not require blood or serum. Instead, urine samples are tested for the presence of hCG. The presence of the hormone in urine is a strong indication of pregnancy. 

Urine hCG qualitative tests do not show the specific hormone level, so it cannot be used to determine the proper development of a pregnancy. The test can also result in false negatives and false positives. However, some urine tests are highly sensitive and can detect lower hCG levels, resulting in early pregnancy detection. 

Although urine hCG qualitative tests can be accurate, many OTC urine tests do not detect hyperglycosylated hCG. In simple terms, early pregnancy can easily go undetected with urine tests. 

A qaualitative hCG blood test is more specific and sensitive than a urine pregnancy test. However, the latter is more comfortable for many women, more convenient, affordable, has a quicker turnaround, and does not require the presence of a healthcare professional or medical prescription.

Estimated Cost of hCG Test

Generally, a blood pregnancy test costs more than at-home pregnancy tests. The cost can also increase if the test has to be repeated several times. If you have insurance, it can cover the blood test; otherwise, you will have to pay from your pocket. 

The average cost of qualitative hCG blood tests starts anywhere from $34 and can exceed $150 depending on the lab and extra tests included. On the other hand, a quantitative test has an average starting cost of $35 and can go as high as $400, depending on the additional tests to be conducted.

Summary

Qualitative hCG tests are very sensitive and can easily pick up the presence of hyperglycosylated hCG – the essential molecule or component responsible for preventing early pregnancy loss. Early pregnancy detection can protect the fetus from possible harm and potential miscarriage. 

Although hCG qualitative might not be a cheap option, it can set your mind at ease since it is more reliable than most over-the-counter urine tests. A blood test performed in a controlled environment and under the supervision of a healthcare professional is more likely to be trusted than a urine pregnancy test that can go wrong because you didn’t follow the instructions to the latter.  Ordering a Qualitative hCG test is easy and can be ordered without a Doctor’s note online at Walk-In Lab.  

Sources 

  1. Gnoth C., Johson S. (2014). Strips of hope: Accuracy of home pregnancy tests and new developments. Geburtshilfe Frauenheilkd 2014 Jul; 74(7): 661–669. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4119102/
  2. Sharma A., Kumar P. (2012). Understanding implantation window, a crucial phenomenon. Journal of Human Reproductive Sciences 2012 Jan-Apr; 5(1): 2–6. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3409914/

Betz D., Fane K. (2020). Human chorionic gonadotropin (hcg). Treasure Island (FL): StatPearls Publishing 2020 Jan. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK532950/

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