Negative βhCG and Molar Pregnancy: The Hook Effect

Authors

  • Isabel Lobo Antunes Gynaecology and Obstetrics Department. Hospital Garcia de Orta. Almada. Portugal.
  • Joana Curado Gynaecology and Obstetrics Department. Hospital Garcia de Orta. Almada. Portugal.
  • Ana Quintas Gynaecology and Obstetrics Department. Hospital Garcia de Orta. Almada. Portugal.
  • Alcides Pereira Gynaecology and Obstetrics Department. Hospital Garcia de Orta. Almada. Portugal.

DOI:

https://doi.org/10.20344/amp.8603

Keywords:

Chorionic Gonadotropin, beta Subunit, Human, Hydatidiform mole

Abstract

Molar pregnancy, included in gestational trophoblastic disease, is a benign pathology with ability to metastasize, usually occurring with excessively high βhCG levels. Clinical scenario is usually a woman in extremes of reproductive age presenting with amenorrhoea, pain and vaginal blood loss; signs derived from high βhCG levels may be present (hyperthyroidism, hyperemesis). Diagnosis is based on a positive pregnancy test – usually a qualitative urinary test. The limitation of this test results from its inability to become positive in presence of markedly high levels of βhCG, saturating the antigens used – known as the ‘hook effect’. With the widespread use of gynaecological ultrasound cases of molar pregnancy have been diagnosed in timely fashion. We describe a case referred as a degenerating fibroid, with a negative urinary pregnancy test. Transvaginal ultrasound was highly suggestive of molar pregnancy, which was confirmed with a quantitative βhCG test, allowing for timely treatment. The importance of a high index of suspicion for this pathology is tremendous to avoid the devastating consequences of a delayed diagnosis.

Downloads

Download data is not yet available.

Downloads

Published

2017-09-29

How to Cite

1.
Lobo Antunes I, Curado J, Quintas A, Pereira A. Negative βhCG and Molar Pregnancy: The Hook Effect. Acta Med Port [Internet]. 2017 Sep. 29 [cited 2024 Mar. 28];30(9):656-8. Available from: https://actamedicaportuguesa.com/revista/index.php/amp/article/view/8603

Issue

Section

Case Report