Birth weight is the actual weight of the baby determined immediately after delivery. The average birth weight in the United States varies between 3,000 and 3,600 g, depending on factors such as race, size of the parents, and gender (boys are heavier). Low birth weight is a leading cause of infant mortality and morbidity. (Collins and David, 1990) It also represents an enormous economic cost to society, both in short-term medical costs and long-term loss of human capital. Rates of low birth weight ...