β-Adrenergic Agonists for Preterm Labor

The infant mortality rate has become a benchmark in measuring progress toward U.S. health objectives. Approximately 40,000 infants die in the United States each year before reaching their first birthday. The overwhelming risk factor for infant mortality is low birth weight; indeed, two thirds of all infants who die before the age of one year weigh less than 2500 g at birth.¹ During the 1980s there was a steady increase in the incidence of preterm delivery,² the most important cause of low birth weight. Clearly, national strategies aimed at reducing infant mortality must include efforts to prevent preterm birth. On…