May 5 2020
What was the PRISM trial?
The PRISM trial was the largest ever randomised trial in miscarriage prevention. Researchers at the Tommy’s National Centre for Miscarriage Research recruited more than 4000 women from 48 hospitals in the UK. The study evaluated the effects of giving progesterone to women with early pregnancy bleeding.
What were the findings of the PRISM trial?
Overall, there was a 3% increase in the live birth rate for the group of women who received progesterone, compared with a placebo, but the finding was associated with some statistical uncertainty. However, a clear benefit was found for women who were experiencing early pregnancy bleeding and a history of (any number of) previous miscarriages. The higher the number of previous miscarriages, the greater the live birth rate, with progesterone treatment.
For women who had 1 or 2 previous miscarriages, and had current pregnancy bleeding, progesterone was associated with a 4% increase in live births. For women with 3 or more previous miscarriages, and had current pregnancy bleeding, progesterone was associated with a 15% increase in live births.
How will this impact clinical practice?
Tommy’s researchers have now recommended that progesterone treatment should be considered for women with early pregnancy bleeding and a history of any number of previous miscarriages. The recommended regimen is 400mg progesterone pessary to be used twice daily from the time of presentation with bleeding to 16 weeks of gestation.
"I experienced 3 heart-breaking miscarriages before the PRISM trial. My husband and I had got to the point where we were devastated and lost. The trial helped us to feel we were doing something positive and gave us hope that the outcome could be different. The personal impact of miscarriage can be long term and far reaching. It’s clear that providing progesterone to those at risk would not only have significant benefits for women and their families, but also for the NHS."
Faye took part in the PRISM trial in 2016 after experiencing recurrent miscarriage.
Read Faye's story here.
Tommy’s has produced an information sheet about progesterone treatment for women and their families Download it here.