Supplementary Material for: Impact of Placental Position and Type on Placenta Accreta Spectrum and Adverse Perinatal Outcomes: A Study Based on Magnetic Resonance Imaging

Objective: To investigate influence of placental position and type on occurrence of Placenta Accreta Spectrum (PAS) and to analyze their correlation with adverse perinatal outcomes.
Methods: This retrospective study included 270 pregnant women who delivered at the Affiliated Hospital of Guangdong Medical University and Huizhou Central People’s Hospital between January 2021 and December 2023. Placental position, type, and related imaging features were assessed using Magnetic Resonance Imaging (MRI) and compared with PAS and perinatal outcomes. Logistic regression was used to analyze the associations between placental position, type, and PAS, as well as adverse outcomes.
Results: There were significant differences between the PAS group and the non-PAS group in terms of pregnancy history, cesarean section history, delivery history, history of placenta previa, antepartum hemorrhage, and intraoperative blood loss. Lateral wall/fundus placenta location (OR=4.984, 95% CI: 1.376–18.050, P=0.014) and complete placenta previa (OR=3.160, 95% CI: 1.321–7.558, P=0.010) were significantly associated with the occurrence of PAS.
Conclusion: Placental location and the type of placenta previa were significantly associated with the occurrence of PAS and adverse perinatal outcomes. In future clinical management, particular attention should be paid to placental location and type, especially in cases of lateral wall/fundus placenta and severe placenta previa. Individualized monitoring and intervention strategies should be implemented to improve both PAS-related and overall perinatal outcomes.