The relationship between placenta prvia with obstetric risk factor:a report of 427 cases

Objective To define the clinical obstetric risk factors associated with placenta previa.Methods Hospital records were reviewed of all cases of placenta prvia confirmed histologically between January 2002 and June 2008.Additionally,we reviewed the records of all women with placenta previa and 2 135 randomly selected simple singleton controls,all those undergoing our hospital during the same period.Data on potential risk factors for placenta previa development were carefully extracted from medical records,reviewed,and compared with a control group of women Multiple logistic regression analysis was used to identify independent clinical risk factors for placenta prvia.Results Among 36 669 deliveries,427(1.16%) were complicated by histologically confirmed placenta previa.Risk factors for placenta previa included maternal age of,or greater than 30 years especially 35 years(OR:2.3-2.6;95%CI:1.6-3.8);and abortions(OR:2.0-3.2;95%CI:1.3-6.8)more than one previous delivery(OR:1.4-3.2;95%CI:1.2-5.7),aprior preterm birth(OR:4.6;95%CI:3.8-6.1) history of previous cesarean sections(OR:1.6-2.8;95% CI:1.3-4.7),history of previous placenta previa(OR:6.2;95%CI:3.6-8.2).Uterine malformation(OR:5.6;95% CI:3.3-7.5).Conclusion The most important obstetric factors for placenta previa development advanced maternal age especially 35 years,3 or more previous pregnancies,parity of 2 and more,rising number of previous abortions,and history of previous cesarean section,aprior preterm birth,history of previous placenta previa and Uterine malformation.