Comparing transcervical balloon with osmotic dilators for cervical preparation prior to procedural abortion: A noninferiority randomized trial

• Published in: Contraception (Stoneham) 2024-12, Vol.140, p.110550, Article 110550
• Main Authors: Liu, Serena M., Henkel, Andrea, Meza, Pamela, Shorter, Jade M., Cahill, Erica, Blumenthal, Paul D., Shaw, Kate A.
• Format: Article
• Language: English
• Subjects: Abortifacient Agents, Nonsteroidal - administration & dosage; Abortion, Induced - methods; Adult; Cervical preparation; Cervix Uteri; Dilatation - instrumentation; Dilatation - methods; Dilation and evacuation; Female; Humans; Mifepristone - administration & dosage; Misoprostol - administration & dosage; Patient Satisfaction; Polymers; Pregnancy; Pregnancy Trimester, Second; Second-trimester abortion; Transcervical balloon; Young Adult
• ISSN: 0010-7824; 1879-0518; 1879-0518
• DOI: 10.1016/j.contraception.2024.110550

This study aimed to compare cervical preparation with transcervical balloon to osmotic dilators for second-trimester procedural abortions. We performed an unblinded, randomized, noninferiority trial of people undergoing second-trimester procedural abortion at 18 + 0 to 23 + 6 weeks' gestation. We randomized participants to either overnight osmotic dilators (Dilapan-S) or transcervical balloon (Foley). Both groups received overnight mifepristone and preprocedural misoprostol. We powered the study on mean difference in procedure duration, a noninferiority limit of 5 minutes. We compared preprocedure cervical dilation and the need for additional dilation and, using a 100-point visual analog scale, measured physician satisfaction and ease of procedure, and participant pain and satisfaction. We recruited 32 participants at a single academic center. Although procedure time (minutes) was similar (balloon: 22.6 ± 8.9 vs Dilapan-S: 22.4 ± 12.8, p = 0.96), noninferiority was not met (mean difference, 0.2 minutes; 95% CI, −7.8 to 8.2). Cervical dilation >2 cm was more likely after Dilapan-S (100% vs 62.5%, p = 0.02). Placement was well tolerated with similar time (minutes) for insertion (balloon: 4.8 ± 1.0, Dilapan-S: 5.1 ± 2.3, p = 0.64) and maximum pain (median) with insertion (balloon 39 [5–78], Dilapan-S: 39 [0–100], p = 0.92). Pain immediately postinsertion was higher for Dilapan-S (33 [0–100] vs 18 [0–50], p = 0.046) and similar for maximum pain overnight, participant satisfaction, and likelihood to recommend. Complications were minor and similar between groups (p = 0.60). While significantly more people with transcervical balloon required mechanical dilation, the difference in operative time was clinically negligible. The transcervical balloon was well tolerated and acceptable by participants. Clinicians experienced in mechanical dilation may consider a transcervical balloon as a lower-cost tool for second-trimester abortion cervical preparation. ClinicalTrials.gov: NCT05099991