Ectopic pregnancy with undetectable serum and urine beta-hCG levels and detection of beta-hCG in the ectopic trophoblast by immunocytochemical evaluation.
BACKGROUND
Ectopic pregnancies associated with negative urine or serum pregnancy test by radioimmunoassay usually demonstrate either nonviable trophoblast or absent production of beta-hCG by the ectopic pregnancy.


METHODS
We report a patient with intra-abdominal hemorrhage caused by a ruptured ampullary ectopic pregnancy who had undetectable serum and urine beta-hCG levels (less than 5 mIU/mL). Immunoperoxidase staining of the ectopic trophoblastic tissue obtained at surgery revealed both beta-hCG and placental alkaline phosphatase.


CONCLUSIONS
Negative serum and urine pregnancy tests can occur even though beta-hCG produced by the viable ectopic trophoblastic tissue can be demonstrated by immunoperoxidase staining.
Maccato
M L
ML
Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas.
Estrada
R
R
Faro
S
S
D000328:Adult; D006063:Chorionic Gonadotropin / Q000032:analysis*; D018997:Chorionic Gonadotropin, beta Subunit, Human; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000209:etiology; D006801:Humans; D007124:Immunoenzyme Techniques; D010446:Peptide Fragments / Q000032:analysis*; D011247:Pregnancy; D011258:Pregnancy Tests; D011274:Pregnancy, Tubal / Q000175:diagnosis*; D012422:Rupture, Spontaneous; D014327:Trophoblasts / Q000737:chemistry*
D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D010446:Peptide Fragments