Abstract
Preterm birth is one of the most important problems in medicine today, with an alarming frequency and economic impact. This article reviews recent research findings, specifically addressing the following interventions: cerclage placement, detection and treatment of infections, progesterone administration, antibiotics in preterm labor and the use of tocolysis. The effectiveness of these interventions is presented in terms of the number needed to treat and number needed to harm. At present, most of our interventions fail to demonstrate benefit in terms of the prevention of preterm birth and improvement of neonatal outcomes. Use of progesterone may hold promise but whether we will develop effective interventions to reduce risks for all women remains to be seen.