A novel approach for the early prediction and prevention of placenta accreta spectrum and severe peripartum hemorrhage in patients with complete placenta previa: leveraging three-dimensional placental topography, cervical length, and dilatation parameters on magnetic resonance imaging.

Background: To evaluate the reliability of placental volume and other magnetic resonance imaging (MRI) markers for predicting placenta accreta spectrum and severe peripartum hemorrhage in patients with complete placenta previa.

Methods: This single-center retrospective cohort study was conducted at a tertiary care facility and included 216 pregnant women diagnosed with complete placenta previa. Two radiologists, blinded to each other's assessments, independently evaluated the prenatal placental magnetic resonance imaging (pMRI) findings of 150 singleton pregnancies that met the inclusion criteria and were delivered in the third trimester. The three-dimensional placental volume (from the S1 and S2 sectors), cervical canal length (CCL), and degree of cervical canal dilatation (CCD) were compared with clinical and pathological findings. Univariate and multivariate logistic regression analyses identified risk factors for placenta accreta spectrum (PAS) and severe peripartum hemorrhage (SPPH). Receiver operating characteristic (ROC) curve analysis determined the cutoff values of significant predictors.

Results: Univariate analysis revealed significant risk factors for PAS, including decreased cervical canal length (odds ratio [OR] = 1.330, p < 0.001), increased cervical canal dilation (OR = 1.869, p < 0.001), decreased S1 volume (OR = 1.008, p < 0.001), and increased S2 volume (OR = 1.008, p < 0.001). Multivariate analysis confirmed that cervical canal length was an independent risk factor (odds ratio [OR] = 1.253, p = 0.03). Significant predictors of severe peripartum hemorrhage included decreased cervical canal length (odds ratio [OR] = 0.406, p = 0.006), increased cervical canal dilatation (OR = 3.22, p < 0.001), decreased S1 volume (OR = 1.079, p = 0.017), and increased S2 volume (OR = 1.032, p < 0.001), all of which were confirmed as independent risk factors. ROC analysis demonstrated high precision for MRI markers, with area under the curve values above 0.8 for critical predictors of PAS and severe peripartum hemorrhage, confirming their reliability (all p < 0.001).

Conclusion: This study emphasizes the pivotal role of three-dimensional placental volume measurements in the S1 and S2 sectors, along with cervical canal length and dilation, in predicting PAS and severe peripartum hemorrhage in patients with complete placenta previa. Integrating these advanced MRI markers into prenatal care can enhance early detection, improve clinical decision-making, and ultimately improve maternal and fetal outcomes.