Pregnancy Testing - False Positive Pregnancy Test

Pregnancy Test:

Home pregnancy tests detect a pregnancy by the presence of the Human Chorionic Gonadotropin (hCG) hormone – a glycoprotein hormone that is produced by the placenta after fertilization takes place - in a woman's urine. The hCG hormone is present in very small and sometimes undetectable amounts in the urine during the initial stages of the pregnancy, so if you are using a home pregnancy test kit to find out if you are pregnant, you should preferably carry out the test at least 8 days after conception or after you've missed a period. Home pregnancy tests, so long you follow their instructions exactly, can be up to 99 percent accurate.

False Positive Pregnancy Test:
Sometimes the pregnancy test may come out positive, when, in fact, you are not pregnant. This is what is known as a false positive pregnancy test. A false positive pregnancy test is not very common, and there are many reasons why it may happen.

Causes behind a False Positive Pregnancy Test:

Taking the pregnancy test at the wrong time:
As mentioned, pregnancy is detected by the presence of the Human Chorionic Gonadotropin (hCG) hormone and this hormone is present in very low levels during the initial stages of pregnancy. So if you test too early, the test may fail to detect the hCG and give the wrong result. The hCH hormone can also sometimes be produced by tissues other than the placenta and so a woman who is not pregnant may get a positive result. It's advisable to wait at least eight days before taking a pregnancy test and testing the first urine of the day, as this has hCG in concentrated amounts. Or you can get a test done every two days – if you are pregnant, the hCG level will show a steady increase.

Improper testing:
It is necessary to read 'how-to' instructions carefully when using a home pregnancy test kit and to follow them correctly. Most tests require you to read the result only within a specified time period, and it is very important that you follow this instruction, using a clock to record the time to be absolutely accurate. Not checking within the specified time or checking after the time frame has elapsed can lead to the wrong result.

Evaporation line:
When urine is tested in some home pregnancy tests and the test is positive, the urine usually changes color and a colored line shows up in the testing strip area. You should check for this line in the specified time, which may be around five minutes after testing. If you don't check in time, the urine in the test area can dry up and give rise to an evaporation line. Evaporation lines may also arise due to a particular kind of urine composition. In any case, the evaporation line shows up as a colorless or a light grey line that can be seen very faintly or only if held up in the light to be seen, and is mistakenly taken as a positive test result. If an evaporation line shows with the test, you should retest again in a day or two days for a correct result.

Chemical Pregnancy:
Many women become pregnant and then miscarry very early on – according to research, this seems to be a common phenomenon with many first-time pregnancies. This early miscarriage is called a Chemical Pregnancy. So a woman may get a positive result from her home pregnancy test and then miscarry.

Influence of medication or health problems on the home pregnancy test:
If you are on any medication that contains the hCG hormone, it will affect your pregnancy test and give out a false positive pregnancy test result. Women who are undergoing fertility treatments should especially keep this in mind. So it's important to talk to your doctor both before and after you do a home pregnancy test and go for a thorough check-up.

Defective pregnancy test:
Before buying a home pregnancy test kit, remember to check the expiration date on the pack. You won't get correct test results from a pack that's expired, which may sound obvious, but in some cases needs to be stated. There is also a chance that the test kit may be a defective one, leading again to the wrong test results.

If you think you have made a mistake in the testing, you should get another pregnancy test done after two or more days. Don't depend wholly on the home pregnancy test kit results though, whatever the result. Visit your doctor and have a blood test for pregnancy. This is much more accurate.