The PRISM trial

The PRISM trial is an important research study which is looking at whether progesterone can prevent miscarriage in women with early pregnancy bleeding.  We provide information about it here – and further down the page you can read comments from two women who took part in the trial.

PRISM is a randomised, double-blind, placebo-controlled trial:

Randomised: The women who take part will be given either the treatment drug (progesterone) or a placebo – a dummy drug that has no active ingredients. A computer makes the selection so it’s completely random.

Double-blind: The women in the study won’t be told whether they are taking the active medicine or the placebo – and neither will their doctors. So both are blinded to this information.

Placebo-controlled: Half the women in the study will have the active medicine and half (the controlswill have the placebo.  The medicine that they receive will look exactly the same to them and their doctors, but a completely separate group will keep a record of which women have progesterone and which have the placebo.

If you might be interested in taking part in the PRISM trial, here’s what you need to know:

Who can take part?

The researchers are recruiting women who:

  • are aged 16 – 39
  • are in the first 12 weeks of pregnancy and are having vaginal spotting or bleeding
  • a scan shows an ongoing pregnancy
  • are willing to be selected at random to have either the treatment or a placebo, without knowing which they are given.

What would I need to do?

If you agree to take part, you will be given a pack of capsules and asked to insert two capsules twice a day (morning and evening) into your vagina with your fingers (rather like using a tampon). You will be asked to do this until 16 weeks of pregnancy.

The trial team will collect most of their study information about your pregnancy and your baby from your hospital notes but they may need to contact you to check some details.

You can read Amanda and Faye’s accounts of taking part in the trial, at the bottom of this page.

Where is it taking place?

The trial will recruit women from centres across England and Scotland. The following hospitals are currently recruiting patients:

  • Barnstaple: North Devon District Hospital
  • Birmingham: Birmingham Heartlands Hospital
  • Birmingham: Birmingham Women’s Hospital
  • Bradford:  Bradford Royal Infirmary
  • Bristol: St Michael’s Hospital
  • Burnley: General Hospital
  • Burton: Queen’s Hospital
  • Carlisle: Cumberland Infirmary
  • Chertsey: St Peter’s Hospital
  • Coventry: University Hospital Coventry
  • Edinburgh: Royal Infirmary of Edinburgh
  • Exeter: Royal Devon & Exeter Hospital
  • Glasgow: Glasgow Royal Infirmary
  • Hull:  Hull & E Yorks Women and Children’s Hospital
  • Huntingdon: Hinchingbrooke Hospital
  • Keighley: Airedale General Hospital
  • Leeds: St James’s University Hospital
  • Liverpool: Liverpool Women’s Hospital
  • London: Chelsea & Westminster Hospital
  • London: Kings College Hospital
  • London: St Mary’s Hospital
  • London: St Thomas’s Hospital
  • London:  University College London Hospital
  • London: West Middlesex University Hospital
  • London: Whipps Cross University Hospital
  • Manchester: St Mary’s Hospital
  • Merseyside: Whiston Hospital
  • Middlesborough: James Cook University Hospital
  • Newcastle: Royal Victoria Infirmary
  • Nottingham:  Queen’s Medical Centre
  • Oxford: John Radcliffe Hospital
  • Plymouth: Derriford Hospital
  • Portsmouth: Queen Alexandra Hospital
  • Preston: Royal Preston Hospital
  • Redhill: East Surrey Hospital
  • Scunthorpe: Scunthorpe General Hospital
  • Sheffield: Royal Hallamshire Hospital
  • Stoke-on-Trent: Royal Stoke University Hospital
  • Sunderland: Sunderland Royal Hospital
  • Taunton: Musgrove Park Hospital
  • Telford: Princess Royal Hospital
  • Walsall: Walsall Manor Hospital
  • Warrington: Warrington Hospital
  • Wolverhampton: New Cross Hospital
  • Worcester: Worcester Royal Hospital

New centres are opening regularly.

If you would like more information, or have questions or concerns about the trial, please contact the PRISM office at You may also like to visit the trial website.

If your questions are less medical/scientific and more about feelings or concerns, do contact us at or call us on 01924 200799.


Some personal views

Amanda took part in the PRISM trial. She writes:

“At 6 weeks pregnant I was bleeding and went to the Early Pregnancy Unit at University College Hospital, London.  Here I was offered the chance to take part in the PRISM trial.

“With the potential outcome of not miscarrying I was very keen to learn more.  I was told about the possible side effects, and also that I might only be taking a placebo. I read up on how successful taking progesterone only has been in other countries. I felt that it was a great opportunity to not only support the trial for women in this country but also giving my fetus an extra chance of not miscarrying. So I agreed to take part.

“During the trial I was given fantastic one to one advice from the PRISM research team. It was extremely reassuring knowing that I had a point of contact thought my pregnancy, someone who I could contact any time. She was easy to talk to and answered any of my questions, putting my mind at rest. I also had additional scans, to see the progress of my fetus, which was fantastic.

“I was a little uncomfortable about using the (vaginal) pessaries to start with and worried – would I use them properly, would they have side effects. After literally 24 hours I was inserting the pessaries with ease and with no discomfort. I found wearing a pantie liner useful for any discharge that I had.

“I travel a lot for work which was another worry but taking the pills didn’t affect my day to day life at all.

“I don’t know if I took the progesterone or a placebo, but I am so pleased that I was lucky enough to take part in the trial.  I am now 38 weeks pregnant, with a healthy baby girl on her way.”


Faye also took part in the PRISM trial, and writes:

“I was signed up to the PRISM trial after having bleeding in early pregnancy. After experiencing three miscarriages since the birth of my son it was a relief to feel like we were doing something proactive in this pregnancy.

“I obviously don’t know whether the trial made a difference to this pregnancy’s outcome, but I was absolutely delighted when our baby daughter was born. We’ve waited two years for her arrival and experienced a lot of heartache along the way so I just wanted to say thank you for offering hope to more parents through these trials.”