Overview of investigations before medical abortion

Investigations before medical abortion may be performed by the referring practitioner or the abortion provider. They include¹:

• ultrasound scan (transvaginal or transabdominal)
• quantitative serum human chorionic gonadotrophin (hCG) measurement
• blood haemoglobin measurement if there are risk factors for anaemia (eg coeliac disease, vegetarian diet, heavy menstrual bleeding)
• screening for sexually transmitted infections (chlamydia and gonorrhoea) before prescribing, using a self-collected vaginal swab or a first-pass urine sample, so that infection can be treated before medical abortion; see also Sexually transmitted infections. Alternatively, testing can occur on the day of prescribing if the practitioner is confident that prompt treatment will be possible if infection is identified. Treat any positive results as soon as they are available, to minimise the risk of pelvic inflammatory disease.

Before treatment, the provider of medical abortion should perform a baseline quantitative serum hCG measurement, ideally on the day the mifepristone is taken. This is compared with the serum hCG measurement 7 days after the mifepristone is taken; a drop to below 20% of baseline confirms there is no continuing viable pregnancy.