We will plan an update of the following section of the guideline:
The OPPTIMUM study on vaginal progesterone prophylaxis compared with placebo for pre-term labour and birth was highlighted by guideline stakeholders as potentially impacting on the guideline recommendations.
This was a randomised controlled trial carried out in women at risk of preterm birth (because of previous spontaneous birth at ≤34 weeks and 0 days of gestation, or a cervical length ≤25 mm, or because of a positive fetal fibronectin test combined with other clinical risk factors for preterm birth. The results suggest that progesterone had no significant effect on the primary obstetric outcome (odds ratio adjusted for multiple comparisons [OR] 0.86, 95% confidence interval [CI] 0.61–1.22) or neonatal outcome (OR 0.62, 0.38–1.03), nor on the childhood outcome (cognitive score, progesterone group versus placebo group, 97.3 [SD 17.9] versus 97.7 [SD 17.5]). These results were considered to impact on the following guideline recommendations:
1.2.1 Offer a choice of either prophylactic vaginal progesterone or prophylactic cervical cerclage to women:
With a history of spontaneous preterm birth or mid-trimester loss between 16+0 and 34+0 weeks of pregnancy and
In whom a transvaginal ultrasound scan has been carried out between 16+0 and 34+0 weeks of pregnancy that reveals a cervical length of less than 25 mm.
1.2.2 Offer prophylactic vaginal progesterone to women with no history of spontaneous preterm birth or mid-trimester loss in whom a transvaginal ultrasound scan has been carried out between 16+0 and 34+0 weeks of pregnancy that reveals a cervical length of less than 25 mm.
The results of the OPPTIMUM study were discussed with the guideline committee chair who indicated that 'the OPPTIMUM study reduces confidence in the recommendation to prescribe progesterone to prevent preterm birth'. On that basis, the proposal to update the section in the guideline on prophylactic vaginal progesterone was discussed with additional topic experts at a workshop for the pregnancy guideline suite. Topic experts agreed that this new evidence could impact on the guideline recommendations and felt that an update was warranted. However, as this was placebo controlled trial, and the guideline currently recommends prophylactic vaginal progesterone or prophylactic cervical cerclage, then the results of this study will only inform one of the recommended choices. No additional literature searches were conducted to identify additional studies in this area.
Decision: The following review question should be updated:
What is the clinical effectiveness of prophylactic progesterone (vaginal or oral) in preventing preterm labour in pregnant women considered to be at risk of preterm labour and birth?
This exceptional surveillance review was carried out to allow us to consider the impact of the study described above on the guideline recommendations. We did not search for new evidence relating to this guideline as part of this focused surveillance.
After considering the new evidence and views of topic experts, we decided that a partial update is necessary for this guideline.
See how we made the decision for further information.
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