Vaginal progesterone combined with cervical pessary in preventing preterm birth: a meta-analysis

Vaginal progesterone and cervical pessary are both shown to be effective in preventing preterm. We conducted a meta-analysis to evaluate whether the combination of these two interventions has any additional benefit in preventing preterm birth and improving perinatal outcomes in asymptomatic women with a singleton gestation who had a midtrimester sonographic short cervix compared with vaginal progesterone alone.

Five databases were searched from their inception to 21 February 2019. We estimated relative risk (RR) and 95% confidence intervals (CIs) for dichotomous outcomes. The primary outcome was preterm birth <34 weeks, and second outcomes included low birth weight (LBW) delivery, perinatal death, and neonatal intensive care unit (NICU) admission.

Three RCTs with a total of 820 participants were identified. Cervical pessary had no significant prevention effect of preterm birth when combined with vaginal progesterone compared to the control group with vaginal progesterone alone (RR = 0.91; 95% CI, 0.47-1.77). No significant difference has been revealed between groups in LBW delivery (RR = 1.13; 95% CI, 0.86-1.48), perinatal death (RR = 1.27; 95% CI, 0.58-2.78) and NICU admission (RR = 1.24; 95% CI, 0.84-1.85).

Comparing with vaginal progesterone alone, cervical pessary plus vaginal progesterone did not reduce the rates of preterm birth at <34 weeks of gestation. There was no difference in LBW delivery, perinatal death, and NICU admission. We need more evidence to balance the benefit and side effects on the combination of vaginal progesterone and cervical pessary for preventing preterm birth.