Abnormally low hCG in a complete hydatidiform molar pregnancy: The hook effect

Abstract

► The hook effect occurs with extremely high levels of hCG, saturating detection antibodies, leading to falsely low laboratory results. ► In the literature, descriptions of the hook effect are rare in cases of gestational trophoblastic diseases. ► If unrecognized, this can lead to delayed therapy or mismanagement of care.

Mola completa coexistente con feto vivo normal: caso clínico y revisión de la literatura

“…Dichos niveles se explican por el «efecto gancho»; este fenómeno falsea los niveles de B-hCG por sobresaturación de los anticuerpos empleados para la detección de esta hormona 11 y es más frecuente con niveles de B-HGC mayores de 500.000 mUI/ml 12 . Por todo esto, la B-HGC tiene un valor limitado cuando se usa de forma aislada para el diagnóstico de las gestaciones molares y siempre ha de evaluarse conjuntamente con los demás datos disponibles 11 .…”

Molar Pregnancy Presenting as a Large Abdominal Mass and ‘Hook Effect’

“…Histology confirmed a complete mole, which has a 10% risk of malignant change. When there is a high index of suspicion of molar pregnancy but Inconclusive or negative β-HCG results, samples should be further evaluated by serum quantification appropriate sample dilution [1][2][3][4].…”

A twin pregnancy with a hydatidiform mole and a coexisting live fetus: prenatal diagnosis, treatment, and follow-up

“…Several singularities of this clinical case should be emphasized. The first are the serum hCG measurements at falsely low levels, characteristic for the high-dose Hook effect ( 10 , 11 ) . Negative or falsely low hCG doses are a rare biochemical phenomenon present in patients with very high levels of hCG (usually >1,000,000 IU/L), which makes its correct measurement very hard, and may lead to a delay in the diagnosis of molar gestation.…”