Socio-economic factors associated with preterm delivery in Greece: a population-based study.

A total population sample of singleton births to mothers with certain last menstrual period dates was identified from the Greek National Perinatal Survey of April 1983. Two groups were considered (3116 primigravidae and 6524 multigravidae) with preterm rates of 5.9% and 8.4% respectively. Of all 17 factors considered, primigravidae showed unadjusted significant associations between preterm delivery and marital status, region of mother's residence, maternal occupation, maternal education and paternal education level. Multigravidae preterm deliveries were associated with marital status, mother's age at marriage, father's age at marriage, mother's age at delivery, mother's education, father's education and maternal smoking at the end of the pregnancy. Logistic regression was used to identify the socio-economic and demographic characteristics independently associated with preterm delivery. For primigravidae, the only significant factors were maternal marital status and region of the country. For multigravidae, significant factors were maternal age at delivery, marital status and smoking habit at the end of pregnancy.