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What is the hook effect in regards to pregnancy testing and why does it occur? Would it effect a blood test?
2 doctors weighed in

Dr. Cornelia Franz
Pediatrics
1 doctor agrees
In brief: Yes
A very rare cause of false negative results occurs when very, very, high concentrations of HCG are present.
This is called the high-dose hook effect. Urine and blood can be negative. Diluting the urine and/or getting an ultrasound can confirm pregnancy. http://www.pregnancylab.net/2011/05/false-negative-pregnancy-tests.html.

In brief: Yes
A very rare cause of false negative results occurs when very, very, high concentrations of HCG are present.
This is called the high-dose hook effect. Urine and blood can be negative. Diluting the urine and/or getting an ultrasound can confirm pregnancy. http://www.pregnancylab.net/2011/05/false-negative-pregnancy-tests.html.
Dr. Cornelia Franz
Dr. Cornelia Franz
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