Prematurity at birth: trends, racial disparities, and epidemiology.

While infant mortality rates have continued to decline in the U.S., low birth weight and preterm rates have dramatically increased. Although the combination of factors that underlies these trends has not been fully described, there is growing concern that an appreciable part of the rise in prematurity rates stems from efforts taken to improve the survival of these high-risk infants. While advancements in medical technology and practice, augmented by improvements in prenatal care use, may have adversely effected prematurity rates and played a role in broadening racial disparities in pregnancy outcomes, they have positively impacted infant survival. Although many risk factors for prematurity have been identified, there are presently few areas for effective prevention. Accordingly, there is little encouragement for a downturn in prematurity rates in the near future. The prospect of continuing growth in the annual number of surviving preterm infants in the U.S. highlights the need for early detection and treatment of developmental problems for these high-risk survivors, and emphasizes the importance of assuring that needed support services are available to these children and their families. Copyright 2002 Wiley-Liss, Inc.