Reproductive and obstetrical outcomes after treatment of retained products of conception: hysteroscopic removal vs ultrasound-guided electric vacuum aspiration, a prospective follow-up study

Abstract

Background: Traditionally, curettage has been the most widely performed surgical intervention for removing retained products of conception. However, hysteroscopic removal is increasingly performed as an alternative because of the potentially lower risk of intrauterine adhesions and higher rates of complete removal. Until recently, studies comparing curettage with hysteroscopic removal regarding reproductive and obstetrical outcomes were limited, and data conflicting.

Objective: This study aimed to assess reproductive and obstetrical outcomes in women wishing to conceive after removal of retained products of conception by hysteroscopy or ultrasound-guided electric vacuum aspiration.

Study design: This was a prospective long-term follow-up study, conducted in 3 teaching hospitals and 1 university hospital. Patients were included from April 2015 until June 2022 for follow-up, either in a randomized controlled, nonblinded 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 of retained products of conception ranging from 1 to 4 cm were eligible. Surgical procedures in the randomized controlled trial were hysteroscopic morcellation or ultrasound-guided electric vacuum aspiration. In the cohort study, hysteroscopic treatment included 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 after removal of retained products of conception, resulting in a cohort of 171 women after hysteroscopic removal and 90 women after removal by ultrasound-guided vacuum aspiration. Respectively, 92 of 171 women (53.8%) in the hysteroscopic removal group and 56 of 90 (62.2%) in the electric vacuum aspiration group wished to conceive (P=.192). Subsequent pregnancy rates were 88 of 91 (96.7%) after hysteroscopic removal and 52 of 56 (92.9%) after electric vacuum aspiration (P=.428). The live birth rates were 61 of 80 (76.3%) and 37 of 48 (77.1%) after hysteroscopic removal and electric vacuum aspiration, respectively (P=.914), with 8 of 88 pregnancies (9.1%) in the hysteroscopic removal group and 4 of 52 (7.7%) 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 of 80 (16.3%) in the hysteroscopic removal group and 11 of 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 effects on subsequent live birth rate, pregnancy rate, time to conception, or pregnancy complications. Reproductive and obstetrical outcomes after removal of retained products of conception are reassuring, albeit with a high risk of placental complications.

Keywords: dilation and curettage; hysteroscopic cold loop resection; hysteroscopic morcellation; live birth rate; miscarriage; placental complications; placental remnants; pregnancy complications; pregnancy rate; time to conception.