Factors associated with preterm birth in Cardiff, Wales: II. Indicated and spontaneous preterm birth

OBJECTIVE: Our purpose was to examine and contrast associations of risk factors with spontaneous preterm birth and indicated preterm birth. STUDY DESIGN: Separate multiple logistic regression analyses were performed of indicated and spontaneous preterm births in a large database of births in Cardiff, Wales. RESULTS: Spontaneous preterm births were associated with young maternal age, low maternal weight, low or high parity, previous abortion, smoking, and early pregnancy bleeding. Indicated preterm births were associated with older age, low weight, previous stillbirth, bacteriuria, and early pregnancy bleeding. CONCLUSION: Spontaneous and indicated preterm births have different overall profiles of association with pregnancy risk factors.