BACKGROUND AND PURPOSE:

• Efficacy of vaginal progesterone to prevent preterm birth and adverse perinatal outcomes in women with short cervix has been questioned in recent literature
• Romero et al. (AJOG, 2018) examined whether vaginal progesterone prevents preterm birth and improves perinatal outcomes in asymptomatic women with a singleton gestation and a short cervix ≤25mm

METHODS:

• Systematic Review and meta-analysis
• Literature search of eligible randomized controlled trials (RCTs) comparing vaginal progesterone with placebo/no treatment in women with a singleton gestation and a midtrimester sonographic cervical length ≤25 mm
• Primary outcome: Preterm birth <33 weeks of gestation
• Secondary outcomes: Preterm birth <37, <36, <35,
• <34, <32, <30 and <28 weeks of gestation and other adverse perinatal outcomes and neurodevelopmental and health outcomes at 2 years of age

RESULTS:

• Data was pooled from 974 women with a cervical length ≤25 mm participating in five high-quality trials
• Vaginal progesterone was linked to a significantly reduced risk of preterm birth <33 weeks of gestation (relative risk [RR] 0.62, 95% CI 0.47-0.81, P=0.0006; high-quality evidence)
• Vaginal progesterone significantly decreased the risk of preterm birth <36, <35, <34, <32, <30 and <28 weeks of gestation, spontaneous preterm birth <33 and <34 weeks of gestation, respiratory distress syndrome, composite neonatal morbidity and mortality, birthweight <1500 and <2500 g, and admission to the neonatal intensive care unit (RRs from 0.47 to 0.82; high-quality evidence for all)
• There were seven (1.4%) neonatal deaths in the vaginal progesterone group and 15 (3.2%) in the placebo group (RR 0.44, 95% CI 0.18-1.07, P=0.07; low-quality evidence)
• Maternal adverse events, congenital anomalies, and adverse neurodevelopmental and health outcomes at 2 years of age did not differ between groups

CONCLUSION:

• Vaginal progesterone is safe, can decrease preterm birth risk and improve perinatal outcomes in women with short cervix regardless of previous history of preterm birth
• Vaginal progesterone, in this study, was associated with a 41% reduction in the frequency of a composite outcome of neonatal death combined with common neonatal complications seen in preterm newborns
• The authors calculate that a universal transvaginal cervical length screening program and treatment with vaginal progesterone for those with a cervical length ≤25 mm would prevent 31,800 preterm births <34 weeks of gestation and 19,800 cases of major neonatal morbidity or mortality

Learn More – Primary Sources:

Vaginal Progesterone for Preventing Preterm Birth and Adverse Perinatal Outcomes in Singleton Gestations with a Short Cervix: A Meta-Analysis of Individual Patient Data

Related ObG Topics:

SMFM Statement: Choice of Progestogen for Preterm Birth Prevention

Vaginal Progesterone to Prevent Preterm Birth in Twins

Do Progestogens Prevent Preterm Birth in Symptomatic Pregnancies with a Short Cervix?