Vaginal progesterone, oral progesterone, 17‐OHPC, cerclage, and pessary for preventing preterm birth in at‐risk singleton pregnancies: an updated systematic review and network meta‐analysis

BACKGROUND: Recent progesterone trials call for an update of previous syntheses of interventions to prevent preterm birth. OBJECTIVES: To compare the relative effects of different types and routes of administration of progesterone, cerclage, and pessary at preventing preterm birth in at-risk women overall and in specific populations.