Patient: What would explain a pregnancy blood test returning HCG levels below 1 but several pregnancy tests from all different brands (none expired) coming back positive DAYS (2) after the blood was taken? My doctor says “huh, weird”, but that’s not really cutting it. Either HCG leaves the blood quicker than it leaves the urine and this was an early miscarriage, a theory the nurse assistant says is not true (she claims it leaves the urine quicker than the blood), or something seems to be very very wrong. I read somewhere this could be an early sign of some different rare cancers? Deeply confused why my doctor seems to be unperturbed about this while saying “yea, I have no idea why that would happen”.
Symptoms: Positive urine pregnancy test, negative blood test (under 1 HCG)
Doctor: Hello,Thanks for the query to ATD for an opinion,If multiple urine pregnancy tests have been positive as you said and that the blood serum beta hcg test is negative, even though serum beta hcg is a more sensitive and specific test, it is not possible that urne pregnancy test remains positive and hcg test comes negative for pregnancy. There is certainly a dichotomy and the report of serum beta hcg is false from that lab. You must repeat the test from another lab and for confirmation of an ongoing pregnancy , get a transvaginal ultrasound done to check for decimal reaction and gestational sac inside the uterus which shall confirm or negate the pregnancy more definitively even though the test results are confusing.Your concern about beta hcg secreting tumours is again irrelevant as the levels of hcg in such tumours are more than a lakh like gestational trophoblastic disease, germ cell tumour of ovary. So in either case an ultrasound shall be definitive.I hope i have answered your query in detail,Wishing you good health,Regards