Article Text

Download PDFPDF
Accuracy of a point-of-care test for quantifying human chorionic gonadotrophin (hCG) in the management of pregnancy of unknown location in an abortion service
  1. John Joseph Reynolds-Wright1,
  2. Peter Main1,
  3. Sharon T Cameron1,2
  1. 1 Chalmers Centre for Sexual Health, NHS Lothian, Edinburgh, UK
  2. 2 University of Edinburgh, Edinburgh, UK
  1. Correspondence to Dr. John Joseph Reynolds-Wright, Chalmers Centre for Sexual Health, NHS Lothian, Edinburgh EH39ES, UK; jjrw{at}doctors.org.uk

Abstract

Introduction Women may seek abortion at gestations when there is no visible intrauterine pregnancy on ultrasound scanning. Clinical protocols for pregnancy of unknown location (PUL) require measurement of serum human chorionic gonadotrophin (hCG), with the National Institute for Health and Care Excellence recommending that values above 1500 IU/L be further investigated to exclude ectopic pregnancy. Our aim was to determine whether a point-of-care test (POCT) could be used instead of laboratory serum hCG measurement.

Methods Over 12 months, women who presented to an abortion service with a PUL had a POCT for blood or urine hCG and laboratory serum hCG measurement. The POCT machine used provides a discrete hCG value below 1000 IU/L and above this gives results as a range. The sensitivity and specificity of the POCT in identifying cases where laboratory serum hCG results were above 1500 IU/L were calculated.

Results A total of 118 women presented with a PUL, of whom 70 had a POCT on blood (n=49) or urine (n=21) and a corresponding laboratory serum hCG. The sensitivity of the blood POCT was 0.67 (95% CI 0.38 to 0.87) and the specificity was 0.97 (95% CI 0.83 to 0.99). The sensitivity of the urine POCT was 0.25 (CI 0.01 to 0.78) and the specificity was 0.94 (CI 0.69 to 0.99).

Conclusion Although both the blood and urine POCTs had a high level of specificity, neither test was acceptably sensitive. While promising, this POCT for hCG is not sufficiently reliable to replace laboratory serum hCG testing in the management of women with PUL in an abortion service.

  • abortion
  • service delivery
  • family planning service provision
  • audit
  • point of care testing
View Full Text

Statistics from Altmetric.com

Footnotes

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.