via Pubmed
Ned Tijdschr Geneeskd. 2014;157:A6336.
[Pregnancy tests: urine versus blood pregnancy tests].
[Article in Dutch]
Abstract
In this article, we discuss possible explanations for the discrepancy in results between urine and blood pregnancy tests. The first patient, a 26-year-old woman, had breast tenderness, was tired and suffered from abdominal pain. A urine pregnancy test
was negative, but blood human chorion gonadotropin (hCG) concentration
was 455 U/l (reference value < 6 U/l). It was concluded that the
patient was pregnant and she was followed in the outpatient clinic.
Three days later she suffered blood loss and her hCG levels returned to
normal. The diagnosis was a spontaneous abortion. The second patient, a
45-year-old woman, complained of abdominal pain, nausea and more blood
loss than with a normal period. The urine pregnancy test was negative, but the hCG level in her blood was 470.000 U/l. Echography showed a thickened, irregular endometrium. A molar pregnancy
was suspected and curettage was performed. The hCG level dropped
initially but had increased at follow-up. Persistent trophoblastic
disease was suspected and the patient underwent additional treatment.
