The objective of this contract is to obtain a quantifiable description of behavior and lifestyle differences among pregnant women of different ethnic groups which are known to differ in their rates of low birth weight. The underlying goal is to identify previously undescribed risk factors affecting birth outcome. Interviews will be conducted with pregnant women from a variety of ethnic groups to characterize certain behavioral and sociocultural factors. In addition, birth outcome records for these pregnancies will be obtained as well as demographic descriptors and information about known pregnancy risk.