Impact of early postoperative human chorionic gonadotropin change direction after high-intensity focused ultrasound on ultrasound-guided dilation and curettage outcomes 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).Methods This retrospective study was conducted at Deyang People’s Hospital, Deyang, China. A total of 210 patients with cesarean scar pregnancy (CSP) were enrolled and divided into two groups based on the direction of serum β-hCG change after HIFU: the hCG declining group (n = 75) and 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.Results No significant differences were found in baseline data or HIFU parameters between groups. β-hCG on post-curettage day 1 remained higher in the rising group (p < 0.05), yet the percentage drop from post-HIFU value was similar in two groups (p > 0.05). Median intra-curettage blood loss (10 vs 20 mL), adjuvant haemostatic procedures (4.0% vs 6.7%) and re-intervention (6.7% vs 7.4%) also showed no differences (all p > 0.05).Conclusion In this cohort, a post-HIFU rise or fall in β-hCG was not associated with differences in USg-D&C procedure, blood loss or re-intervention. These findings do not establish equivalence, but suggest that short-term β-hCG direction alone may not be a reliable predictor of procedural outcomes.