Placental 3D Doppler and uterine artery Doppler for predicting adverse outcomes in placenta accreta: a retrospective cohort study

Background Placenta accreta spectrum (PAS) poses high maternal morbidity from adverse pregnancy outcomes (APOs), yet uterine artery Doppler has limited predictive value, and the additive role of three‑dimensional power Doppler (3D‑PD) remains unclear.Methods A retrospective study was carried out on 180 patients with PAS, who were divided into an APO group (n = 76) and a non-APO (n = 104) group. Placental 3D-PD parameters, including the vascularisation index (VI), flow index (FI) and vascularisation-flow index (VFI), as well as uterine artery flow parameters, including the pulsatility index (PI), resistance index (RI) and systolic/diastolic ratio (S/D), were collected and compared between the two groups. Multivariate logistic regression was used to identify independent predictors. Internal validation was performed with 1,000 bootstrap resamples, and calibration was evaluated using the Hosmer–Lemeshow test. The predictive value of each parameter and of a combined model was assessed using receiver operating characteristic curves.Results The overall incidence of APOs in patients with PAS was 42.22% (76/180). The APO group had higher VI, FI and VFI values but lower PI, RI and S/D values than the non-APO group (all p < 0.05). After adjusting for gestational age at delivery, all six parameters remained independent predictors (p < 0.05). Each single parameter showed only poor predictive value, with AUCs ranging from 0.604 to 0.656. The combined model based on all six parameters demonstrated better predictive ability (AUC = 0.793; 95% confidence interval: 0.726–0.859), with a sensitivity of 83.65% and a specificity of 61.84%.Conclusion APOs in patients with PAS are associated with increased placental vascularisation and reduced uterine artery resistance. The combined model outperforms any single parameter and may aid in early risk stratification.