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

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], 0.420.80), <35 weeks (RR, 0.69; 95% CI, 0.550.88), and <28 weeks (RR, 0.50; 95% CI, 0.300.81); respiratory distress syndrome (RR, 0.48; 95% CI, 0.300.76); composite neonatal morbidity and mortality (RR, 0.57; 95% CI, 0.400.81); birthweight <1500 g (RR, 0.55; 95% CI, 0.380.80); admission to neonatal intensive care unit (RR, 0.75; 95% CI, 0.590.94); and requirement for mechanical ventilation (RR, 0.66; 95% CI, 0.440.98). 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.