Estimation of Incidence and Correlation of Abnormally Invasive Placenta Score With Estimated Blood Loss in Placenta Accreta Spectrum Cases: A Retrospective Cohort Study From a Tertiary Center in South India.

BACKGROUND: Placenta accreta spectrum (PAS) disorders are life-threatening obstetric complications associated with significant maternal morbidity and mortality. Early diagnosis and risk stratification are critical for optimal management. This study aimed to estimate the incidence of abnormally invasive placentas (AIPs) in singleton pregnancies and evaluate the correlation between AIP scores and estimated blood loss (EBL) in PAS cases. METHODS: This retrospective cohort study was conducted at tertiary center in south India, from January 2019 to March 2024. Singleton pregnancies diagnosed with PAS were included. The AIP score, based on ultrasonographic features, was used to categorize patients into moderate (score < 8) and high risk (score 8-12) groups. Maternal and neonatal outcomes, including EBL, hysterectomy rates, and ICU admissions, were analyzed. Statistical analysis included Spearman's correlation, chi-square tests, and logistic regression. RESULTS: Among 52 041 deliveries, 84 PAS cases were analyzed (incidence: 1.6 per 1000 births). The high-risk AIP group (n = 73, 86.9%) had significantly higher EBL (median: 4500 vs. 2500 mL, p = 0.012), transfusion requirements (median: 6 vs. 2 units, p = 0.02), and hysterectomy rates (88%). AIP score correlated moderately with EBL (ρ = 0.403, p < 0.001). Placenta percreta was associated with higher AIP scores (p < 0.001). CONCLUSION: The AIP scoring system effectively predicts the risk of massive hemorrhage and surgical complexity in patients with PAS. High AIP scores predict worse maternal outcomes, underscoring the importance of multidisciplinary care at tertiary centers.