Vaginal progesterone in women with an asymptomatic sonographic short cervix in the midtrimester decreases preterm delivery and neonatal morbidity: a systematic review and metaanalysis of individual patient data

Am J Obstet Gynecol. 2012 Feb;206(2):124.e1-19. doi: 10.1016/j.ajog.2011.12.003. Epub 2011 Dec 11.


Objective: To determine whether the use of vaginal progesterone in asymptomatic women with a sonographic short cervix (≤ 25 mm) in the midtrimester reduces the risk of preterm birth and improves neonatal morbidity and mortality.

Study design: Individual patient data metaanalysis of randomized controlled trials.

Results: Five trials of high quality were included with a total of 775 women and 827 infants. Treatment with vaginal progesterone was associated with a significant reduction in the rate of preterm birth <33 weeks (relative risk [RR], 0.58; 95% confidence interval [CI], 0.42-0.80), <35 weeks (RR, 0.69; 95% CI, 0.55-0.88), and <28 weeks (RR, 0.50; 95% CI, 0.30-0.81); respiratory distress syndrome (RR, 0.48; 95% CI, 0.30-0.76); composite neonatal morbidity and mortality (RR, 0.57; 95% CI, 0.40-0.81); birthweight <1500 g (RR, 0.55; 95% CI, 0.38-0.80); admission to neonatal intensive care unit (RR, 0.75; 95% CI, 0.59-0.94); and requirement for mechanical ventilation (RR, 0.66; 95% CI, 0.44-0.98). There were no significant differences between the vaginal progesterone and placebo groups in the rate of adverse maternal events or congenital anomalies.

Conclusion: Vaginal progesterone administration to asymptomatic women with a sonographic short cervix reduces the risk of preterm birth and neonatal morbidity and mortality.

Publication types

  • Meta-Analysis
  • Research Support, N.I.H., Extramural
  • Review
  • Systematic Review

MeSH terms

  • Administration, Intravaginal
  • Female
  • Humans
  • Pregnancy
  • Pregnancy Trimester, Second
  • Premature Birth / prevention & control*
  • Progesterone / administration & dosage
  • Progesterone / therapeutic use*
  • Progestins / therapeutic use*
  • Risk
  • Treatment Outcome


  • Progestins
  • Progesterone