Prevalence and risk factors associated with preterm birth in Iran

Introduction: Preterm birth is a leading cause of perinatal mortality and long term morbidity, Present study was conducted to determine prevalence and risk factors associated with preterm birth in Ardabil, Iran. Materials and methods: A cross – sectional study conducted between Nov 2010 and July 2011 in all three maternal hospitals in Ardabil. All the live newborns during the study period were investigated. Of 6705 live births during the study period 346 births occurred in < 37 weeks were taken as a case and 589 normal neonates were taken as a control.Data were obtained after delivery from review of prenatal and hospital delivery records. Univariate and multivariate logistic regression analysis were applied to obtain magnitude of association between independent variables and preterm birth. Results: The incidence of preterm birth was 5.1% and history of previous preterm birth (OR=12.7, CI:3.9-40.4, P=0.000), hypertension during pregnancy (OR=7.3, CI:2.1-25.4, P=0.002),Oligohydramnios (OR=3.9, CI:1.6-9.5, P=0.002), spouse abuse (OR=3.7, CI:1.1-11.8, P=0.024), preeclampsia (OR=3.6, CI:1.3-10.3, P=0.014), premature rupture of membrane (OR=3.1, CI:1.9-4.9, P=0.000), bleeding or spotting during pregnancy (OR=2.0, CI:1.0-3.8, P=0.037), Hyperemesis Gravidarum (OR=2.0, CI:1.1-3.8, P=0.015), urinary tract infection in 26-30 weeks of pregnancy (OR=1.8 CI:1.0-3.2, P=0.044), middle and lower social class (OR=1.6, CI:1.0-2.3, P=0.021), Diastolic blood pressure <60mmg (OR=1.5, CI:0.99-2.2, P=0.049), were determined as significant risk factors for preterm birth respectively. Conclusion: These data identify a subgroup of Iranian women at an increased risk for preterm birth, making provision for attentive prenatal care of at risk women are essential to reduce the incidence of LBW.