ABSTRACT
Preterm birth is one of the most challenging problems encountered in modern clinical obstetrics. Not only is it the leading cause of perinatal morbidity and mortality, but its cause and means of prevention are strikingly unclear1. Since 1981, the preterm birth rate has increased by 20%, and identifying patients who are truly at risk for delivering preterm poses a clinical dilemma2. Risk factor scoring predicts, at best, less than half of women destined to deliver preterm3-5. Twin pregnancies are at particular risk, with 56% delivering prior to 37 weeks of gestation, compared with 11.8% in singleton pregnancies6. In addition, although twins account for less than 3% of newborns in the United States, they represent approximately 12% of all premature births and 15% of neonatal mortality6,7.
