O-20:Occurrence of Preterm Deliveries andRelated Factors in 1513 Pregnancies

Background: Considering the important impact of preterm deliveries on neonatal mortality and morbidity, this study was designed to assess the prevalence of preterm deliveries and evaluate possible effective factors of them, in two cities of Iran. Materials and Methods: In this cross-sectional study on 1513 pregnant women attending delivery facilities in educational hospitals of Tehran and Noor City (in north of Iran), the prevalence of preterm deliveries- which were defined as deliveries before 37th week of gestationwere assessed. After obtaining the consent of subjects to enter the study, a complete pregnancy history was obtained from each subject and related reproductive data along with their demographic characteristics were registered, using a general questioner. In performed analysis , p-values