BACKGROUND AND PURPOSE:

• Data is limited regarding the benefit of vaginal progesterone for women with a history of spontaneous preterm birth and a cervix >25 mm
• Conde-Agudelo et al. (AJOG, 2022) assessed the efficacy of vaginal progesterone in preventing preterm birth in this subset of patients

METHODS:

• Post-hoc subgroup analysis of previously published meta-analysis
• Inclusion criteria for original meta-analysis
  • RCTs
  • Studies that compared vaginal progesterone vs placebo or no treatment for recurrent preterm birth prevention
• Subgroup analysis exposure
  • Short cervix ≤25 mm
  • Cervical length >25 mm
• Study design
  • Pooled relative risk was calculated by using a random-effects model
  • GRADE criteria were used to assess the quality of evidence
• Primary outcome
  • Preterm birth <37 and <34 weeks
• Secondary outcomes
  • Maternal and neonatal outcomes

RESULTS:

• 10 trials in original meta-analysis
• Cervical length >25 mm: There was no difference in the frequency of preterm birth <37 weeks between control and progesterone
  • Progesterone: 35.4%
  • Control: 35.4%
  • RR 0.99 (95% CI, 0.84 to 1.16); P=0.88
  • High-quality evidence
• Cervical length ≤25 mm (‘short cervix’): Vaginal progesterone significantly reduced the risk of preterm birth <37 weeks vs control
  • RR 0.72 (95% CI, 0.58 to 0.90)
  • High-quality evidence
• Similar results were found for preterm birth <34 weeks and <28 weeks
• There were no significant differences in the risk of adverse maternal or neonatal outcomes between progesterone and controls

CONCLUSION:

• There is no evidence that vaginal progesterone prevents preterm birth among women with a singleton gestation, a history of spontaneous preterm birth, and a cervical length >25 mm
• The authors state

In summary, our findings reaffirm that vaginal progesterone should be offered to patients with a singleton gestation and a history of spontaneous preterm birth only if they have a midtrimester (18-24 weeks of gestation) transvaginal sonographic cervical length ≤25 mm

Learn More – Primary Sources:

Vaginal progesterone does not prevent recurrent preterm birth in women with a singleton gestation, a history of spontaneous preterm birth, and a midtrimester cervical length >25 mm

Related ObG Topics:

EPPPIC Meta-analysis Results: Progestogens for Preterm Birth Prevention

RCT Results: Vaginal Progesterone or 17-OHPC for Preventing Recurrent Preterm Birth?

Meta-Analysis: Which Interventions are Best for Preventing Spontaneous Preterm Birth?  

Does Vaginal Progesterone Improve Birth Outcomes for Mothers with Short Cervix?