Abstract

Introduction: The challenge in medical abortion is to reliably determine success of treatment within a short time interval, with the aim of improving evaluation of medical abortion outcomes. This can be done clinically using ultrasound (US) and/or hCG testing (urine human chorionic gonadotropin). The systematic use of US may lead to unnecessary surgical intervention and may be a barrier to the use of medical abortion when US is not accessible. Furthermore, US cannot be used in case of very early medical abortion with no confirmed intrauterine pregnancy at initiation of treatment. Serum hCG is highly reliable to judge on-going pregnancy and levels detected in urine correlate with serum levels. Self-assessment of the urine hCG test has proven to be effective and highly acceptable to women. The aim of this review is to describe the use of hCG testing for medical abortion outcomes.
Methods: An extensive literature search was performed using MedLine, with keywords “hCG” AND “abortion” and “abortion” AND “follow-up”, to identify publications in English from 2003 to 2016. A total of 910 references were found, out of which 35 including information on hCG testing were considered.
Results: This review confirms that low-sensitivity urine hCG tests are highly reliable for determining medical abortion outcomes up to 63 days gestation. Their high sensitivity and specificity allow for shortening the time interval to accurately determine success of treatment.
Conclusion: Self-assessment using a low-sensitivity urine hCG test is effective in identifying on-going pregnancy while increasing women’s autonomy by reducing in-clinic visits.

Keywords: hCG; Medical abortion follow-up; Low-sensitivity urine hCG test