Tinari S, Buca D, Cali G, et al. - Risk factors, histopathological correlations and diagnostic accuracy of prenatal imaging were examined in pregnancies complicated by posterior placenta accreta spectrum (PAS) disorders. From MEDLINE, EMBASE and CINAHL, researchers identified 20 studies for inclusion. 92.8% (107/114; 17 studies) of pregnancies complicated by posterior PAS showed presence of placenta previa, while 76.1% (53/88; 11 studies) of women had had prior uterine surgery, mainly a Cesarean section (CS) or curettage and 82.5% (66/77; 10 studies) were multiparous. Overall, the most commonly reported risk factors for posterior PAS included placenta previa, prior uterine surgery and multiparity. Diagnostic accuracy of ultrasound was noted to be very low for detecting these disorders prenatally.