Wrong results with blood pregnancy tests a blood test might not detect human chorionic gonadotropin hcg even when a woman is pregnant if the test is done too early.
False positive pregnancy blood test results.
First a quick summary.
A false negative test is negative but you re pregnant can occur if the blood pregnancy test was performed too early.
It may cause a false positive reading on an at home pregnancy test particularly if the test is taken too early.
Though very rare a false positive blood test happens with a low positive blood pregnancy test the urine test is negative and there is no pregnancy.
Chemical pregnancies are common and often occur for no reason.
But they can cause the body to start producing hcg which could get picked up on a pregnancy test and cause a false positive reading.
Other medications can also cause false positive pregnancy tests.
Most over the counter pregnancy tests measure the levels of hcg in a woman s urine.
Intact hcg reduced the number of false positive pregnancy test results from 13 to 1 a 92 reduction 95 ci 64 99 corresponding to a reduction in the false positive rate from 38 95 ci 22 56 to 3 95 ci 1 15.
After an abortion or miscarriage a home pregnancy test may produce a false positive result since the levels of hcg in the body may still be relatively high.
A phantom hcg causes a positive blood pregnancy test without being pregnant.
If there s a false positive test result the test indicates that a woman is pregnant when in fact she isn t.
It s also possible to get a false positive result if your body produces certain types.
Taking a home urine pregnancy test.
A false positive test result a positive human chorionic gonadotropin hcg test result when you are not pregnant can occur for a variety of reasons.
As with urine home pregnancy tests it is possible to end up with false results both negative and positive from a blood pregnancy test.
Human blood normally contains many different types of antibodies.