Can vaginal progesterone prevent preterm labour?

We will discuss “Prevention of preterm delivery with vaginal progesterone in women with preterm labour (4P): randomised double-blind placebo-controlled trial” by the 4P trial group from 29 April 2015 for 7 days.

*This paper has been made FREE-TO-VIEW. We are also on LinkedIn: (simply ask to join)!


Linked article: This article is commented on by ER Norwitz, “Clarifying when to recommend progesterone to prevent preterm birth: clear as mud“. To view this mini commentary visit


Start date: 29 April 2015 (the discussion will open for 7 days)

First hosted discussion session(s) starts at: BST 7pm (UK time)

Host: @BlueJCHost

Platforms: Twitter and LinkedIn

The Blue Journal Club is an international journal club on women’s health research based on Twitter (as @BlueJCHost). We start our conversation on the last Wednesday of every month and use the hashtag #BlueJC for our tweets. Simply add this hashtag (“#BlueJC”) to each tweet and we will capture it. Each #BlueJC opens for 7 days with an advertised start time. All BJOG #BlueJC papers also have complementary slide sets suitable for face-to-face journal clubs with your local colleagues. You can access the slide set of this paper here (data S1).

The discussion points are attached below (quoted from the published manuscript)


A woman, 32 weeks pregnant, attends antenatal assessment unit with regular and painful uterine contractions. She describes two contractions every 10 minutes. She had one previous preterm delivery at 33 weeks of gestation and this is her second pregnancy. Transvaginal ultrasound on admission shows her cervical length to be 20 mm. Antenatal corticosteroids and tocolysis with atosiban have just been initiated. She asks, “Is there anything else you can do to stop the baby coming early again?”

Description of research

Participants Women presenting with preterm labour (24+0 to 33+6 weeks) to 29 centres in Switzerland and Argentina, started on tocolysis for less than 48 hours
Intervention 200 mg of vaginal progesterone daily (self-administered)
Comparison Placebo

Primary outcome: delivery before 37 weeks of gestation

Secondary outcomes: delivery before 32 and 34 weeks, side-effects, duration of tocolysis, re-admissions for signs and symptoms of preterm labour, length of hospital stay, and neonatal morbidity and mortality

Study design A multicentre, randomised, double-blind, placebo-controlled trial

Discussion Points

  • What are the clinical indications for vaginal progesterone? Are they based on robust evidence?
  • What are the advantages and disadvantages of prospective registration of clinical trials (
  • What are the potential reasons for a steering committee to recommend stopping study enrolment early?
  • Should a trial be allowed to stop because it is suspected that evidence of harm may become apparent?
  • How did the early closure of this clinical trial influence its results?
  • Critically appraise this trial using the Critical Appraisal Skill Programme (CASP) checklist for randomised controlled trials (available from
  • Can you summarise the available evidence in a single sentence?
  • How would the results of this study influence your practice?

Suggested reading

  • Khan KS, Hills R. Can we trust the results of trials that are stopped early? BJOG. 2006;113:766-8.
  • DAMOCLES Study Group, NHS Health Technology Assessment Programme. A proposed charter for clinical trial data monitoring committees: helping them to do their job well. Lancet. 2005;365:711-22.

For those who want to understand hashtags, this may be a useful guide. For an introduction to #BlueJC, please refer to BJOG 2013;120:657–60. Follow @BlueJCHostthis blog and our Facebook page to receive news about #BlueJC.