Pregnancy Tests (Urine Vs Blood) Things You Should Know


There are options for those wanting to do a pregnancy test. There is the do-at-home urine test kits that are 97 to 99% accurate according to their manufacturers or the hCG blood tests that are done at a laboratory.

The one you choose may depend on several factors like cost, ease of use, convenience, and the time it takes for results, among others. However, there is only one that is confirmatory, and that is the blood test.

You can use urine test kits to test if you are pregnant or not but a blood test may be needed to confirm that it is actually so. The blood test is more accurate as it can detect smaller amounts of hCG and is less prone to errors. However, that is not to say, that urine tests are not accurate. They are accurate! But if a confirmation is needed, an hCG blood test is requested.

Urine Pregnancy Tests

Urine pregnancy tests are very common. Actually, they are done more often than the hCG blood test for many reasons, one of them being that they are widely available at drug stores and can be purchased online.

Urine tests are very accurate, although, if instructions are not followed properly and the timing is off, it can give wrong results. In that case, it is not the test kit that is bad but rather the person using it made an error.

Urine test kits detect hCG in urine 12 to 14 days after ovulation. By that time hCG levels are higher in the body and urine tests can detect it.

Pros of Urine Pregnancy Tests:

Urine tests have many advantages. Many of which are the reasons why women prefer it over hCG blood tests. Here are several of them below:

More accessible: Urine pregnancy tests are widely available over-the-counter at pharmacies and certain stores online, making them very accessible to anyone who wants to purchase and use them at home. That allows for privacy.

Very convenient: Urine tests can be done at home, making it very convenient for women to test if they are pregnant in the comfort of their home. These tests come with clear instructions, and the results are typically available within a few minutes.

Affordable: Urine tests are generally inexpensive compared to other methods of pregnancy testing, such as blood tests or ultrasound scans. That makes them more affordable for many individuals.

Quick results: Urine tests provide rapid results, typically within a few minutes. This is much faster than obtaining results from a blood test. Immediate feedback can help alleviate any anxiety that women may have and provide information for any decisions that need to be made.

Cons of Urine Pregnancy tests:

Timing limitations: Urine tests is unable to detect pregnancy as early as blood tests. Women are recommended to wait until after a missed period to test for more accurate results. This can be challenging for individuals with irregular periods or those who are anxious to know early.

False negatives: In some cases, a urine test may yield a false negative result, especially if taken too early or if the urine sample is diluted. False negatives can occur if the test is performed too soon after conception when hCG levels are still low. If pregnancy is suspected despite a negative result, repeating the test after a few days or consulting your doctor is advisable.

User errors: The accuracy of a urine test relies on proper usage of the test kit supplies. User error, such as not following the instructions, using expired tests, or misinterpreting the results, can lead to inaccurate results. It is important to follow the instructions provided with the test.

Limited information: Urine tests only provide a positive or negative result for pregnancy. They do not provide additional information, such as the stage of pregnancy or the progression of hCG levels.

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Blood Pregnancy Tests

Blood pregnancy tests are utilized less than urine pregnancy test, however, they are more accurate and reliable than urine tests. Blood tests can detect hCG levels as early as 6 to 8 days after ovulation, way before urine tests can. They have a 99% accuracy.

A blood test is sometimes used to confirm a positive result obtained by urine. If a woman tests positive at home after doing a urine test, her doctor may ask her to do an hCG blood test to confirm her pregnancy.

There are two types of blood test: qualitative and quantitative. Qualitative gives a positive or negative result, telling you whether you are pregnant or not. Quantitative shows the amount of hCG that is in the blood and tells various things about a pregnancy.

While a quantitative hCG blood test can be used to find if someone is pregnant, it is generally used to gather more information about the developing fetus, like age and if the pregnancy is going well.

Here are some pros and cons of blood pregnancy tests:

Pros of Blood Pregnancy Tests:

Early detection: Blood pregnancy tests can detect pregnancy at an earlier stage compared to urine tests. Some blood tests can detect pregnancy as early as 6 to 8 days after ovulation, which can be helpful for individuals who want to know about their pregnancy as soon as possible or have irregular periods.

Sensitivity to hCG: Blood tests are generally more sensitive than urine tests. They can detect lower levels of hCG. This higher sensitivity makes blood tests more accurate in detecting very early pregnancies or pregnancies with low hCG levels.

Numerical value: Blood tests can provide quantitative measurements of hCG levels. This means they can not only determine the presence of pregnancy but also indicate the approximate duration of pregnancy. By monitoring hCG levels over time, doctors can assess the progress of the pregnancy.

Confirmation and accuracy: Blood tests are considered more reliable and accurate compared to urine tests. They are less prone to false negatives and can provide a definitive confirmation of pregnancy. This can be particularly important in situations where early confirmation is required, such as for medical or fertility treatment purposes.

Cons of Blood Pregnancy Tests:

Need for healthcare setting: Blood pregnancy tests are done at a medical laboratory or at a doctor’s office. This means they require a visit to a healthcare facility and a phlebotomist to draw a blood sample.

More expensive: Blood tests are usually more expensive than urine tests. Prices can vary depending on the healthcare facility and location.

Time for results: Blood test results may take longer to obtain compared to urine tests. Depending on the laboratory and workload, it can take a few hours to a few days to receive the results. This waiting period may cause additional anxiety or anticipation.

Invasive procedure: Blood tests involve the insertion of a needle to draw a blood sample from a vein. Some individuals may have a fear of needles and feel uncomfortable.

Should I Do a Urine or Blood Pregnancy Test?

It is totally fine to do a urine pregnancy test. Urine tests are pretty accurate and results obtained are reliable. Urine tests are very convenient as you can purchase a kit at a drug store or online and do it at home.

It’s fine too if you want to do a qualitative blood test. If you are thinking of cost, dreading doing a venipuncture, or how long it takes to get results, doing a urine test may be the way to go. The good thing, though, about a blood test is that it is very definitive, meaning the result can be relied upon.

Getting a false negative or making a mistake is more common with urine tests. So, while a urine test is generally accurate and can be relied upon, a doctor may ask you to do a blood test to confirm a urine test result. That’s the only thing.

So, sometimes, you may do a urine test but also end up doing a blood test as well.

Can Urine Test be Negative and Blood Test Positive for Pregnancy?

It is possible to test negative for pregnancy using a urine test kit and positive for pregnancy doing an hCG blood test. Urine tests cannot detect low hCG levels if the test is done too early. Also, if the person has drank a lot of fluids or the urine is diluted, the test kit may not detect hCG in the urine.

The hCG blood test can detect low levels of hCG in the blood. Therefore, while a urine test may not detect low levels of hCG or an early pregnancy, a blood test can.

Why Did I get a Positive Urine Test but Negative Blood Test?

It is possible to get a positive urine test but a negative blood test. I have actually witnessed that with a client. She came into the lab and requested to do an hCG blood test. She had done a urine test at home and it showed positive. But when we did the hCG blood test, it was negative.

There can be false positives like false negatives. It may be that the urine test kit had a defect or something happened that wouldn’t normally happen. The hCG blood test is very accurate and reliable, but, if there are ever doubts, urine or blood testing can be repeated.

There are also other ways like doing an ultrasound to confirm whether you are pregnant or not.

Kadia Constant

Having years of experience in laboratory work and phlebotomy, Kadia Constant enjoys sharing what he has learned.

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