Reproductive and Obstetric Outcomes After Treatment of Retained Products of Conception: Hysteroscopic Removal Versus Ultrasound-Guided Electric Vacuum Aspiration, a prospective follow-up study.

BACKGROUND: Traditionally, curettage is the most widely performed surgical intervention used to remove retained products of conception. However, hysteroscopic removal is increasingly performed as an alternative due to the potentially lower risk of intrauterine adhesions and higher rates of complete removal. Until recently, studies comparing curettage with hysteroscopic removal regarding reproductive and obstetric outcomes were limited, and data conflicting.

OBJECTIVE: To study reproductive and obstetric outcomes in women wishing to conceive after removal of retained products of conception by hysteroscopy or ultrasound-guided electric vacuum aspiration.

STUDY DESIGN: Prospective long-term follow-up study, conducted in three teaching hospitals and one university hospital. Patients were included from April 2015 until June 2022 for follow-up; either in a randomized controlled, non-blinded trial on the risk of intrauterine adhesions after removal of retained products of conception, or in a cohort alongside the randomized trial. Women with an ultrasonographic image suggestive for retained products of conception ranging from 1 to 4 cm were eligible. Surgical procedures in the randomized controlled trial consisted of hysteroscopic morcellation or ultrasound-guided electric vacuum aspiration, while in the cohort hysteroscopic treatment consisted of hysteroscopic morcellation or cold loop resection compared with ultrasound-guided electric vacuum aspiration.

RESULTS: A total of 261 out of 305 patients (85.6%) were available for follow-up resulting in a cohort of 171 women after hysteroscopic removal and 90 women after removal of retained products of conception by ultrasound guided vacuum aspiration. Respectively, 92/171 (53.8%) women in the hysteroscopic removal group and 56/90 (62.2%) in the electric vacuum aspiration group wished to conceive (p=.192). Subsequent pregnancy rates were 88/91 (96.7%) after hysteroscopic removal and 52/56 (92.9%) after electric vacuum aspiration (p=.428). The live birth rate was 61/80 (76.3%) and 37/48 (77.1%) after hysteroscopic removal and electric vacuum aspiration, respectively (p=.914), with 8/88 (9.1%) pregnancies in the hysteroscopic removal group and 4/52 (7.7%) pregnancies in the electric vacuum aspiration group still ongoing at follow-up (p=1.00). The median time to conception was 8.2 weeks (interquartile range 5.0-17.2) in the hysteroscopic removal group and 6.9 weeks (interquartile range 5.0-12.1) in the electric vacuum aspiration group (p=.262). The overall placental complication rate was 13/80 (16.3%) in the hysteroscopic removal group and 11/48 (22.9%) in the electric vacuum aspiration group (p=.350).

CONCLUSION: Hysteroscopic removal and ultrasound-guided electric vacuum aspiration of retained products of conception seem to have no significantly different effect on subsequent live birth rate, pregnancy rate, time to conception and pregnancy complications. Reproductive and obstetric outcomes after removal of retained products of conception are reassuring, albeit with a high risk of placental complications.