Objective: To investigate the prenatal diagnosis

clinical features and perinatal outcomes of placenta accreta spectrum (PAS) in different positions of the placenta. Methods: All pregnant women who delivered at Ｔhe First Affiliated Hospital of Chongqing Medical University from January 2012 to December 2021 and were finally diagnosed with PAS were included. They were divided into three groups depending on the placenta location (anterior

posterior

lateral/uterine fundus). Prenatal diagnosis rate

clinical features and perinatal outcomes among the three groups were compared. Results: A total of 2 070 pregnant women were included. In terms of basic characteristics

gravidity

parity

placenta previa rate

cesarean section times≥2 and previous history of placenta previa was significantly higher in the anterior placenta group (P<0.05). The placental accreta rate

multiple pregnancy

in vitro fertilization

vaginal delivery rate and delivery gestational age in the posterior group were higher than those in the anterior placenta group (P<0.05). In terms of grade of PAS and prenatal diagnosis rate

the incidence of placental increta and percreta in anterior wall was significantly higher than that in posterior wall

and the overall prenatal diagnosis rate of PAS was significantly higher than the other two groups (P<0.05) ; further comparison showed that the prenatal diagnosis rate of placental accreta in anterior wall was significantly higher than the other two groups (P<0.05)

and the diagnosis rate of placental increta in anterior wall was also higher than posterior wall (P<0.05)

and there was no statistically significant difference among the three groups in comparison of placenta percreta. Compared with the preoperative procedure

the abdominal aortic balloon

uterine packing

uterine binding

hysterectomy

and postoperative uterine artery embolization were higher in anterior placenta group (P<0.05). In terms of perinatal outcomes

24 hours blood loss

transfusion of blood products

other organ damage

transfer to intensive care unit (ICU) and postoperative hospital stay were significantly higher in the anterior placenta group (P<0.05). The mean birth weight of neonates in the posterior placenta group was higher than that in the anterior placenta group (P<0.05). Conclusion: The prenatal diagnosis rate of PAS in non-anterior placenta is low

but the rate of severe placenta accreta is higher in anterior placenta

and perinatal outcomes is much worse in anterior placenta. On the one hand

it is necessary to be more vigilant about the occurrence of PAS in posterior placenta

and if necessary

further diagnosis can be made by magnetic resonance imaging (MRI). On the other hand

active multidisciplinary management of pregnant women with prenatal diagnosis of PAS is necessary to improve the perinatal outcomes of these women.