The Timing of Surgical Haemostasis Matters: Prophylactic Versus Therapeutic Uterine Artery Ligation in Placenta Accreta Spectrum—A Retrospective Cohort Study on Blood Loss and Haematological Preservation

ABSTRACT Objective To evaluate the differential impact of early, standard and delayed bilateral ascending branch ligation of the uterine arteries (BUAL) on intraoperative blood loss and postoperative haematological recovery in women with placenta accreta spectrum (PAS). Design Retrospective cohort study. Setting A tertiary referral hospital in Beijing, China. Population A total of 143 women with intraoperatively confirmed PAS undergoing caesarean section (January 2014 to November 2025). Methods: Patients were categorised according to BUAL timing: Early (BUAL within 1 min of fetal delivery if bleeding > 150 mL; n = 32), Standard (BUAL after placental delivery if bleeding reached 400 mL; n = 81) and Delayed (BUAL after placental delivery if bleeding reached 800 mL; n = 30). The primary outcome was intraoperative estimated blood loss (EBL). Main Outcome Measures EBL, and perioperative changes in haemoglobin (Hb), haematocrit (HCT) and platelet count. Results BUAL timing was the decisive determinant of EBL ( p < 0.001). Adjusted risk ratios for EBL were 1.95 (95% CI: 1.31–2.89) for Standard versus Early, and 2.55 (95% CI: 1.52–4.25) for Delayed versus Early, showing a clear dose‐response relationship. While EBL was the strongest negative predictor for Hb and HCT recovery (both p < 0.001), the early strategy provided an independent advantage for platelet recovery, with an adjusted mean increase of 40.0 × 10 9 /L (95% CI: 7.6–72.4; p = 0.016) compared with the Delayed group, even after controlling for EBL. Conclusions In caesarean sections for PAS, early BUAL performed at the earliest sign of bleeding is associated with reduced blood loss. It not only minimises haemorrhage effectively but also appears to preserve platelet counts, suggesting a potential protective mechanism beyond haemostasis. These findings support the consideration of early BUAL in surgical protocols for PAS.