Impact of Early Postoperative Human Chorionic Gonadotropin Trend after High-Intensity Focused Ultrasound on ultrasound-guided Dilation and Curettage Outcomes and Prognosis in Cesarean Scar Pregnancy: A Retrospective Study

Objective: To assess whether the changing direction of serum β-subunit of human chorionic gonadotropin (β-hCG) after high-intensity focused ultrasound (HIFU) and before ultrasound-guided dilation and curettage (USg-D&C) influences procedural safety and outcome in caesarean scar pregnancy (CSP). Design: A retrospective study. Setting: Deyang People’s Hospital, Deyang, China. Population: 210 CSP patients were enrolled and divided into two groups based on the direction of serum β-hCG change after HIFU treatment. Methods: Patients with decreased serum β-hCG post-HIFU were in the hCG declining group (n=75), and those with increased β-hCG were in the hCG rising group (n=135). Baseline features, sonication parameters, blood loss, use of adjuvant haemostasis, re-intervention rate and time to β-hCG normalisation were compared. Main Outcome Measures: blood loss during USg-D&C, re-intervention rate and time to β-hCG normalisation. Results: No significant differences were found in baseline data (age, amenorrhea duration, gestational sac diameter, serum β-hCG) or HIFU parameters (treatment power, sonication time, treatment time, intensity, energy, EEF) between groups. β-hCG on post-curettage day 1 remained higher in the rising group ( p 0.05). Median intra-curettage blood loss (10 vs 20 mL), haemostatic manoeuvres (4.0% vs 6.7%) and re-intervention (6.7% vs 7.4%) also showed no differences (all p > 0.05). Conclusion: A post-HIFU rise or fall in β-hCG does not affect USg-D&C procedure, blood loss or time to hCG normalisation.