Accuracy of Prenatal Ultrasonography for Diagnosis of Placenta Accreta Spectrum and Risk Factors in A Tertiary Center in Southern Iran

Background: Placenta accreta spectrum is one of the most important causes of massive bleeding in the peripartum period. The aim of this study was to determine the accuracy of prenatal ultrasonography for diagnosis of placenta accreta spectrum (PAS) and important risk factors of this pathology were evaluated in this report. Materials and Methods: This is a cross-sectional study conducted at Shiraz University of Medical Sciences during January 2018 to January 2019. All patients who were referred for ultrasound examination of placenta accrete spectrum and surgery in Hafez tertiary center were included. Patients with diagnosis of PAS in pathology were in one group and the others in the second group. All maternal and neonatal and demographic data and surgery complications were gathered in a data form. Results: Ultrasonography was 100% (95% C.I: 94.40%-100%) sensitive, 87.58% (95% C.I; 81.29%-92.36) specific, and 87.58% (95% C.I: 82.44%-91.66%) accurate discriminating PAS from non-PAS patients. From 217 patients, 64 and 153 patients were in PAS and non-PAS group, respectively. There was significantly more age, gravidity, live children, history of D&C, hormonal contraception, and history of previa in PAS group compared with Non-PAS group (p-value<0.05 for all); however, gestational age was significantly lower in PAS group (p-value<0.05). The odds of PAS significantly increase with previa and low-lying placenta OR adj (95% C.I): 114.68 (28.45-462.29). The patients with one C/S OR adj (95% C.I): 29.07(3.80-222.33) and the patients with two C/S OR adj (95% C.I): 106.08(13.79-815.51) were significantly more in PAS group compared with those with no C/S (p-value <0.05 for both). Conclusion: Detection rate of ultrasound examination was good, and it is recommended for women with PAS risk factors. Decreasing the rate of cesarean section and encouraging vaginal birth after cesarean section (VBAC) are the best ways of prevention of this pathology.