Infection as a cause of preterm birth

Prematurity is the most significant problem confronting obstetricians in industrial countries today. Preterm births, defined as those occurring at less than 37 weeks' gestational age, cause approximately 75% of the perinatal mortality and as much as 50% of the long-term neurologic handicap. [I] In the last 20 years, the prematurity rate in the United States has risen from approximately 9.5% to 12%. [2] (Fig. 1) Although tremendous strides have been made in keeping preterm infants alive, there has been less success in reducing the long-term handicap rates among the survivors. [3,4] Much of the mortality and the long-term handicap associated with prematurity occurs in the smallest or earliest gestational age newborns. For example, it is estimated that 60% of the neonatal mortality and many of the long-term handicaps accrue to infants born weighing less than 1000 g and less than 28 weeks' gestational age. Many of these early preterm births occur secondary to an intrauterine infection. [5] This study explores the relationship between infection and preterm birth.