False Positive Pregnancy Blood Test Results

Most over the counter pregnancy tests measure the levels of hcg in a woman s urine.

False positive pregnancy blood test results.

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. Taking a home urine pregnancy test. Molecules made by our immune system that identify and neutralize invaders such as bacteria and viruses. It s also possible to get a false positive result if your body produces certain types.

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. 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. First a quick summary. 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.

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. If there s a false positive test result the test indicates that a woman is pregnant when in fact she isn t. There is another cause of false positive hcg test results that is unique to blood samples. It may cause a false positive reading on an at home pregnancy test particularly if the test is taken too early.

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. A phantom hcg causes a positive blood pregnancy test without being pregnant. A false negative test is negative but you re pregnant can occur if the blood pregnancy test was performed too early. It takes at least seven days after fertilization for the test to become positive.

Human blood normally contains many different types of antibodies.