INTRODUCTION: This study aimed to validate the Sargent risk stratification algorithm for the prediction of placenta accreta spectrum (PAS) severity using data collected from multiple centers and using the multicenter data to improve the model. MATERIAL AND METHODS: We conducted a multicenter analysis using data collected for the IS-PAS database. The Sargent model's effectiveness in distinguishing between abnormally adherent placenta (FIGO grade 1) and abnormally invasive placenta (FIGO grades 2 and 3) was evaluated. A new model was developed using multicenter data from the IS-PAS database. RESULTS: The database included 315 cases of suspected PAS, of which 226 had fully documented standardized ultrasound signs. The final diagnosis was normal placentation in 5, abnormally adherent placenta/FIGO grade 1 in 43, and abnormally invasive placenta/FIGO grades 2 and 3 in 178. The external validation of the Sargent model revealed moderate predictive accuracy in a multicenter setting (C-index 0.68), compared to its higher accuracy in a single-center context (C-index 0.90). The newly developed model achieved a C-index of 0.74. CONCLUSIONS: The study underscores the difficulty in developing universally applicable PAS prediction models. While models like that of Sargent et al. show promise, their reproducibility varies across settings, likely due to the interpretation of the ultrasound signs. The findings support the need for updating the current ultrasound descriptors and for the development of any new predictive models to use data collected by different operators in multiple clinical settings.

• Keywords
• abnormal adherent placenta, abnormal invasive placenta, placenta accreta spectrum, prediction model, probability,
• MeSH
• Algorithms MeSH
• Adult MeSH
• Risk Assessment MeSH
• Humans MeSH
• Placenta Accreta * diagnostic imaging   MeSH
• Predictive Value of Tests MeSH
• Prospective Studies MeSH
• Reproducibility of Results MeSH
• Severity of Illness Index MeSH
• Pregnancy MeSH
• Ultrasonography, Prenatal * MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Validation Study MeSH

INTRODUCTION: The main goal of placenta accreta spectrum (PAS) screening is to enable delivery in an expert center in the presence of an experienced team at an appropriate time. Our study aimed to identify independent risk factors for emergency deliveries within the IS-PAS 2.0 database cohort and establish a multivariate predictive model. MATERIAL AND METHODS: A retrospective analysis of prospectively collected PAS cases from the IS-PAS database between January 2020 and June 2022 by 23 international expert centers was performed. All PAS cases (singleton and multiple pregnancies) managed according to local protocols were included. Individuals with emergent delivery were identified and compared to those with scheduled delivery. A multivariate analysis was conducted to identify the possible risk factors for emergency delivery and was used to establish a predictive model. Maternal outcomes were compared. RESULTS: Overall, 315 women were included in the study. Of these, 182 participants (89 with emergent and 93 with scheduled delivery) were included in the final analysis after exclusion of those with unsuspected PAS antenatally or who lacked information about the urgency of delivery. Gestational age at delivery was higher in the scheduled group (34.7 vs. 32.9, p < 0.001). Antenatal bleeding (OR 2.9, p = 0.02) and a placenta located over a uterine scar (OR 0.38, p = 0.001) were the independent predictive factors for emergent delivery (AUC 0.68). Ultrasound (US) markers: loss of clear zone (p = 0.001), placental lacunae (p = 0.01), placental bulge (p = 0.02), and presence of bridging vessels (p = 0.02) were more frequently documented in the scheduled group. None of these markers improved the predictive values of the model. Higher PAS grades were identified in the scheduled group (p = 0.01). There were no significant differences in maternal outcomes. CONCLUSIONS: Antenatal bleeding and the placental location away from the uterine scar remained the most significant predictors for emergent delivery among patients with PAS, even when combining more predictive risk factors, including US markers. Based on these results, patients who bleed antenatally may benefit from transfer to an expert center, as we found no differences in maternal outcomes between groups delivered in expert centers. Earlier-scheduled delivery is not supported due to the low predictive value of our model.

• Keywords
• US markers, antenatal bleeding, cesarean section, placenta accreta spectrum, predictive model,
• MeSH
• Cesarean Section * statistics & numerical data   MeSH
• Adult MeSH
• Humans MeSH
• Emergencies MeSH
• Placenta Accreta * diagnosis   MeSH
• Retrospective Studies MeSH
• Risk Factors MeSH
• Pregnancy MeSH
• Delivery, Obstetric * statistics & numerical data   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

INTRODUCTION: In cases of placenta accreta spectrum, a precise antenatal diagnosis of the suspected degree of invasion is essential for the planning of individual management strategies at delivery. The aim of this work was to evaluate the respective performances of ultrasonography and magnetic resonance imaging for the antenatal assessment of the severity of placenta accreta spectrum disorders included in the database. The secondary objective was to identify descriptors related to the severity of placenta accreta spectrum disorders. MATERIAL AND METHODS: All the cases included in the database for which antenatal imaging data were available were analyzed. The rates of occurrence of each ultrasound and magnetic resonance imaging descriptor were reported and compared between the Group "Accreta-Increta" (FIGO grades 1 & 2) and the Group "Percreta" (FIGO grade 3). RESULTS: Antenatal imaging data were available for 347 women (347/442, 78.5%), of which 105 were included in the Group "Accreta - Increta" (105/347, 30.2%) and 213 (213/347, 61.4%) in the Group "Percreta". Magnetic resonance imaging was performed in addition to ultrasound in 135 women (135/347, 38.9%). After adjustment for all ultrasound descriptors in multivariate analysis, only the presence of a bladder wall interruption was associated with a significant higher risk of percreta (Odds ratio 3.23, Confidence interval 1.33-7.79). No magnetic resonance imaging sign was significantly correlated with the degree of severity. CONCLUSIONS: The performance of ultrasound and magnetic resonance imaging to discriminate mild from severe placenta accreta spectrum disorders is very poor. To date, the benefit of additional magnetic resonance imaging has not been demonstrated.

• Keywords
• abnormal invasive placenta, magnetic resonance imaging, placenta accreta spectrum, severity, ultrasound,
• MeSH
• Databases, Factual MeSH
• Cohort Studies MeSH
• Humans MeSH
• Magnetic Resonance Imaging standards   MeSH
• Placenta Accreta classification   diagnostic imaging   MeSH
• Prenatal Diagnosis methods   MeSH
• Sensitivity and Specificity MeSH
• Severity of Illness Index * MeSH
• Pregnancy MeSH
• Ultrasonography, Prenatal standards   MeSH
• Check Tag
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Observational Study MeSH
• Geographicals
• Europe MeSH
• United States MeSH