Just over 1 in 4 women reported having preterm contractions during their pregnancy, and one-fourth of these women were hospitalized for preterm labor. The strongest risk factor for experiencing preterm contractions and for subsequent preterm delivery was a preterm or low birth weight delivery in the previous pregnancy. After adjusting for other factors, income and insurance source were associated with experiencing preterm contractions but not with preterm delivery following preterm contractions. Income and insurance type were associated with delivering preterm in the absence of preterm contractions.