Correlation of placental thickness and PAS disorders: findings from MRI.

Abstract

To identify if placental thickness measured from MRI images correlates with placenta accreta spectrum (PAS) disorders. Placental thickness of 245 patients was retrospectively measured from October 2016 to March 2020. The measurement was made at the thickest portion of the placenta on the mid-sagittal plane of the placenta from MRI by two independent radiologists. Surgical report and pathology of the delivered placenta were used as a reference standard. Association between clinical features, placental thickness, and PAS disorders was evaluated with univariate and multivariate analyses. The inter-reader and intra-reader reproducibility of the measurements and receiver operating characteristic curve analysis were also performed. Placental thickness was significantly higher in patients with PAS disorders (3.45cm) than that in patients without PAS disorders (2.90cm) (p < 0.05). Multivariate analyses revealed that prior cesarean section, placenta previa, and placental thickness > 4cm were independent risk factors for PAS disorders. The inter-reader and intra-reader reproducibility of placental thickness measurement were 0.979 (95% CI 0.960-0.989) and 0.981 (95% CI 0.9640-0.990), respectively. The reproducibility of the measurement made from MRI images was high between two radiologists. Patients with PAS disorders had increased placental thickness. Placental thickness > 4cm correlated with PAS disorders.