AMETHYST

• Research type

  Research Study

• Full title

  AMETHYST: A multicentre, double-blind, placebo-controlled randomised trial comparing a combination of mifepristone and methotrexate versus methotrexate and placebo as a medical treatment for tubal ectopic pregnancy.

• IRAS ID

  1010254

• Contact name

  Andrea Woolner

• Contact email

  a.woolner@abdn.ac.uk

• Sponsor organisation

  University of Aberdeen

• ISRCTN Number

  ISRCTN15446999

• Research summary

  Ectopic pregnancy affects 1 in 80 pregnancies. Ectopic pregnancy is the leading cause of death for women in the first 3 months of pregnancy. It occurs when a pregnancy grows in an abnormal location outside the womb, usually within a Fallopian tube. These pregnancies cannot develop normally. As they grow, there is a risk that the tube will burst (‘ruptured’ ectopic pregnancy) causing life-threatening, internal bleeding. Historically, the only treatment was an operation to remove the affected Fallopian tube together with the ectopic pregnancy inside.
  Women value non-surgical treatment options for tubal ectopic pregnancy. Current medical treatment (with a drug called methotrexate) has up to a 30% failure rate whereby women will still require emergency surgery. This trial will investigate if adding mifepristone to standard medical treatment reduces the need for emergency surgery for tubal ectopic pregnancy in women clinically suitable for medical management of tubal ectopic pregnancy. This trial will run in up to 40 UK hospitals and women aged 16 years and older who are are eligible for methotrexate and who have opted for methotrexate, will be invited to take part in our trial. Those who consent will be randomised to receiving either mifepristone tablets or dummy tablets at the same time as their first methotrexate injection. All women will be followed up for 12 weeks after randomisation where among the two groups we will compare the need for emergency surgery, the time for pregnancy hormones in blood tests to come down to non-pregnant levels, the number of hospital visits and second injections of methotrexate required, as well as safety and acceptability of treatment in two groups.

• REC name

  West of Scotland REC 1

• REC reference

  25/WS/0168

• Date of REC Opinion

  16 Dec 2025

• REC opinion

  Further Information Favourable Opinion