How reliable are home pregnancy tests as compared to blood pregnancy tests?

There are two types of pregnancy tests:

Home Pregnancy Tests that use a urine sample at home to test for pregnancy at home.
Blood Pregnancy Tests that use a sample of blood usually done at a doctor’s office.

Both tests detect the presence of a hormone called human chorionic gonadotropin (hCG). This hormone is produced by the placenta shortly after the embryo attaches to the uterine lining and builds up rapidly in your body in the first few days of getting pregnant.

Home Pregnancy Tests:

There are different types of home pregnancy tests and you can use them at home or in a clinic. Most doctors recommend that you wait until the first day of your missed period before taking a home pregnancy test. This is usually about two weeks after conception. However, some tests are more sensitive than others and can be taken earlier.

The first type of home pregnancy tests - dip tests, involve collecting your urine in a cup and dipping a stick into the urine, or putting urine into a special container with an eyedropper.

A second type of home pregnancy tests - midstream tests, involve placing a stick into your urine stream and catching your urine in midstream.

Tests vary in how many minutes you have to wait to get a result. You will be looking for a change in color, a line or symbol (like a plus or minus). All tests come with instructions and it is important that you follow these instructions to get an accurate reading.

Home Pregnancy Tests

Advantages:

Home pregnancy tests are preferred by most because they can be done at home,
Home pregnancy tests are usually low in cost ,
Home pregnancy tests give a fast result, and can be done privately.

Disadvantages:

If not done correctly or taken too early, the home pregnancy test result can be inaccurate.

If you get a negative result and still have symptoms of pregnancy (missed period, nausea, breast tenderness and fatigue), wait a week and take another test. It is highly recommended that you contact your doctor so you can have a blood test done. Also, if you have received different answers on multiple pregnancy tests, it is recommended that you get a blood test done to get an accurate answer.

Blood Tests:

There are two types of blood tests.

A quantitative blood test measures the exact amount of hCG in the blood and
A qualitative hCG blood test gives a simple yes or no answer to whether you are pregnant or not.

Advantages of having a blood test done:

Blood tests can detect a pregnancy earlier than a home pregnancy test (about 7-12 days from possible conception)
Blood tests can measure the concentration of hCG hormone in your blood (this is useful information for your healthcare provider in tracking certain problems in pregnancy)

Disadvantages to having a blood test done:

More expensive than a home pregnancy test (price depends on cost of doctor’s visit and lab fees)
Takes longer to get result
Must be done in a doctor’s office

Reliability comparison:

Home pregnancy tests are around 97% accurate when done correctly. However, a blood test is more accurate, but not necessarily more sensitive. The results depend a lot on the lab, methodology and technique of the blood test performed.

A quantitative blood test, usually called a beta hCG test, measures the exact units of hCG in the blood. That means it will detect even the most minimal level. There is another type of blood test sometimes called a qualitative hCG test. This is a test that simply gives a yes or no answer to whether you are pregnant.

Just like home pregnancy tests, labs vary as to what is considered a positive pregnancy test. Common cutoffs for positive blood tests for pregnancy are 5, 10, and 25 units. A level under 5 is considered negative. A blood test that is only triggered at 25 units of hCG is not any more sensitive than several of the home pregnancy tests.

This entry was posted under About Pregnancy Tests.