We thank Zhao et al.1 for facilitating an important discussion on the future research required to inform clinical practice of uterine evacuations. We concur that our data2 highlights underexplored aspects of surgical instrumentation, ultrasound utilization decisions, and long-term effects on the endometrium. Firstly, within the limitations of a retrospective design, surgical instrumentation patterns did suggest ultrasound guidance may alter surgical technique.2 Prospective studies should explore surgical techniques, which could have implications for reducing uterine trauma and improving fertility outcomes. Secondly, reasons for ultrasound utilization were not addressed due to unavailable data. Our study showed one sonographer ultrasound-guided procedure was recorded as an intraoperative rescue with all other ultrasound-guided cases preoperatively planned. All cases with previous uterine perforation and failed evacuation were performed under ultrasound guidance, highlighting one aspect of decision making.2 Therefore, future studies could contribute to understanding of surgeon preferences to enable ultrasound resource allocations. Thirdly, we agree prospective studies on long term outcomes are extremely important to understand retained products of conception (RPOC) as a nidus for adhesions or subsequent adverse pregnancy outcomes. Zhao et al.1 stated RPOC is linked to intrauterine adhesions and subsequent infertility, independent of whether repeat intervention is performed, based on a systematic review3 of two studies. We are unsure of the authors' interpretation of this study, as solid conclusions could not be drawn due to insufficient information on previous dilatation and curettage (D5 repeat surgery prevalence was higher in our study for blind procedures (OR 1.6. CI 0.5 to 4.8) potentially due to larger residual volumes.2 Finally, postpartum women are a uniquely challenging and high-risk population, with strong evidence of associated complications.2 We believe the higher proportion of complications in blind procedures (18%) and ultrasound guided (14%)2 does highlight the need for larger studies of this group to enable actionable clinical guidelines.1 Your support1 of our findings urging further research on the value of ultrasound guidance during surgery is appreciated. Future studies may confirm our findings which indicate ultrasound guidance alters surgical technique, is utilized for higher risk surgeries, and reduces endometrial trauma. Drafting of article: SD. Critical revision of the article: SD, AQ, ST, and JC. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.
Dowthwaite et al. (Wed,) studied this question.