Abstract

There are contradicting results regarding the effect of previa on pre-eclampsia. Therefore, the aim of the present study was to systematically review the relevant literatures and to determine the association between placenta previa and pre-eclampsia in pregnant women. Electronic scientific databases including Scopus, PubMed, and Web of Science were searched to identify relevant published studies. Two independent authors studied the selected studies and extracted data. I-2 statistics was used to assess the variation across studies. The random effects model was used to assess pooled effect sizes. Data were analyzed through Stata software version 12. The results of the present meta-analysis of nine studies indicated a significant relationship between placenta previa and risk of pre-eclampsia. The odds of pre-eclampsia were 0.55 (95 confidence interval (CI) 0.26-.85) in placenta previa cases compared with the control groups and 0.17 (95 CI 0.07-0.27) in studies with adjustment on confounder variables. Our results showed that placenta previa is associated with a decrease incidence of pre-eclampsia.