Risk factors of placenta previa in the second and third trimester of pregnancy

Placenta previa is a common cause of bleeding in second and third trimester of pregnancy .Evidently; it is associated with high mortality and morbidity in the mother and fetus. This study aimed to determine the risk factors for placenta previa at the center of education, research and treatment of Amir Al-momenin hospital of Semnan.
In this case-control study, medical records of 50 patients with placenta previa and 100 control group (without suffering from placenta previa) randomly from among all pregnant women who admitted in Amir Al-momenin (AS) hospital (Semnan. Iran) subjected over the past ten years (April 2005 to March 2015). Information about the risk of placenta previa was compared between the two groups.
Placenta previa patients comparison to the control group had higher age (31.02±3.34 vs. 26.15±4.53 and P = 0.001), higher number of previous pregnancies (3.42±1.18 vs. 0.94±0.79, P = 0.001), higher history of abortion and curettage (12% vs. 3%, P = 0.038) and higher previous cesarean section (86% versus 23%, P = 0.001); however, previous abortions without curettage (P = 0.531), a history of uterine surgery (P = 0.557), history of infertility (P = 0.637), history of infertility drag use (P = 0.465), history of endometriosis (P = 0.333) and doing hysterosalpangiography (P = 0.571) in the two groups were not significantly different.
Since the increase of age and prior cesarean are the risk factors of placenta previa, the obstetricians should consider these factors during prenatal care and should use appropriate methods of diagnosis and treatment for prevention of placenta previa complications.