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

## TL;DR

This study evaluated how well prenatal ultrasounds can detect placenta accreta spectrum (PAS) and identified risk factors for the condition in a hospital in Iran.

## Contribution

The study provides new evidence on the diagnostic accuracy of prenatal ultrasonography for PAS and highlights key risk factors specific to a Southern Iranian population.

## Key findings

- Prenatal ultrasonography had 100% sensitivity and 87.58% specificity in diagnosing PAS.
- Previous cesarean sections and placenta previa were strongly associated with increased odds of PAS.
- Older age, higher gravidity, and hormonal contraception were more common in PAS cases.

## Abstract

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 DC, hormonal contraception, and history of previa in PAS group
compared with Non-PAS group (p-value0.05 for all); however, gestational age was
significantly lower in PAS group (p-value0.05). 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.