Preterm birth is a continuing obstetric problem that contributes significantly to the incidence of perinatal death and long-term handicap. In this context, various studies have shown preterm births account for between 69% and 83% of neonatal deaths. Despite this, the incidence of preterm birth has remained static for many years. One explanation for this is that the management of preterm labor has altered very little in the past 30 years. Strategies aimed at reducing the incidence of preterm birth include the identification of risk factors that increase the likelihood of preterm delivery. Treatment is then designed to target those risk factors and limit their effect. Although perinatal mortality has declined, mostly due to the improved management of very low birthweight babies rather than prevention of preterm labor, efforts to prevent preterm birth have been largely unsuccessful so far and preterm birth still represents a major health care problem to both developed and developing countries.