Objective: Our purpose was to examine the associations of demographic, social, and medical factors with risk of preterm birth.
Study design: By use of the Cardiff Births Survey, a large database of largely homogeneous (white) births in Wales, multivariable analysis by logistic regression examined the relative importance of risk variables associated with preterm birth.
Results: Significant independent associations with preterm birth were found (in decreasing order of magnitude) for late pregnancy bleeding, preeclampsia-proteinuria, low maternal weight, low maternal age, early pregnancy bleeding, history of previous stillbirth, smoking, high parity, low or high hemoglobin concentration, history of previous abortion, low social class, bacteriuria, and nulliparity.
Conclusion: In this population demographic, social, and medical characteristics of the pregnancies showed significant associations with preterm birth.