Because the primary pathology of preeclampsia appears to be at the maternalfetal interface and is characterized by poor trophoblastic invasion of the uterus and subsequently altered uteroplacental blood flow, uterine changes induced by prior cesarean section may interfere with normal trophoblastic invasion and uteroplacental blood flow in subsequent pregnancies, resulting in preeclampsia. However, little is known about the effect of prior cesarean section on the occurrence of preeclampsia in subsequent pregnancies. The aim of this study was to clarity the risk factors of preeclampsia in the second pregnancy, and the effect of prior cesarean section on the preeclampsia risk in a subsequent pregnancy.