Diagnostic accuracy of hCG measurements alone for determining ectopic pregnancy and viable intrauterine pregnancy

DetailsAdditional comments
Review questionWhat is the diagnostic accuracy of two or more hCG measurements for determining:
in women with pain and bleeding and pregnancy of unknown location?
Need to note how many hCG measurements taken and timing of them. Also need to detail how difference between measurements is being interpreted

Note (if possible) the gestation of pregnancy in included women.

For diagnosis of ectopic pregnancy viability is not the issue – just location.
ObjectivesTo identify the diagnostic accuracy of hCG in determining an ectopic pregnancy or a viable intrauterine pregnancy where there is pregnancy of unknown location. If possible to determine when these should be performed and what thresholds should be used.Report timing of hCG measurements and thresholds used in deciding diagnosis.
Study designExperimental studies of diagnostic accuracy.

Observational studies of diagnostic pathway (prospective and retrospective)
StatusPublished papers
PopulationPregnant women with pain and / or bleeding in a pregnancy of unknown location.

Population includes:

Suspected miscarriage

Suspected threatened miscarriage

Suspected ectopic pregnancy

Population excludes:

Women without pain and bleeding in early pregnancy

Women with multiple pregnancy
NB. At presentation women often do not know they are pregnant. Establishing this is part of the diagnosis.
InterventionBeta human chorionic gonadotrophin measurement/assay – blood/serum samples (2, 3 or more)
ComparatorGold standard:

For ectopic pregnancy: laparoscopy or laparotomy +/-histology

For viable IUP: Repeat ultrasound scan showing viable pregnancy, or laparoscopy
For ectopic pregnancy: laparoscopy or laparotomy with histology to confirm pregnancy tissue where relevant

(Note: if any intervention to confirm pregnancy disrupts viability, this is not a valid reference (gold) standard for this question)
OutcomesConfirmed diagnosis using gold/reference standard
Other criteria for inclusion/exclusion of studiesInclude only developed countries

Exclude non-human studies

Exclude non-English papers

1985 onwards
It was around this time that the first EPAUs were established and hCG measurements started to be used.

From: Appendix D, Review protocols

Cover of Ectopic Pregnancy and Miscarriage
Ectopic Pregnancy and Miscarriage: Diagnosis and Initial Management in Early Pregnancy of Ectopic Pregnancy and Miscarriage.
NICE Clinical Guidelines, No. 154.
National Collaborating Centre for Women's and Children's Health (UK).
London: RCOG; 2012 Dec.
Copyright © 2012, National Collaborating Centre for Women's and Children's Health.

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