Study: Pelvic floor dilator reduces pelvic floor muscle injury during vaginal delivery

Image credit: Alik Mulikov

One of the major concerns is the potential for levator ani muscle (LAM) avulsion, an injury that can lead to pelvic organ prolapse (POP). LAM avulsion occurs in 13% to 36% of individuals following vaginal birth and is significantly linked to subsequent POP beyond the hymen, which affects over half of women with LAM injuries within 6 to 17 years postpartum, writes the authors of the EASE study, recently published in the International Urogynecology Journal.¹

“The current standard of care is to allow the pelvic floor muscles to stretch suddenly as the baby’s head passes through the birth canal, which leads to a full LAM avulsion about 15% of the time,” said urogynecologist and EASE lead investigator Helai Hesham, MD, Columbia University Irving Medical Center, New York.“Because these muscles hold the uterus, bladder, and rectum, in place when these muscles are injured, the patient can experience significant symptoms of sexual, urinary, or fecal dysfunction.”²

To combat this issue, investigators studied the safety and effectiveness of a novel intrapartum electromechanical pelvic floor dilator (IPD) (Prep Device; Materna Medical) to prevent LAM avulsion, which works by slowly stretching the pelvic tissues during labor.

This multicenter, randomized controlled trial included nulliparous individuals planning vaginal delivery at term. Participants were randomized to receive either the IPD or standard labor management. The primary endpoint was the presence of full LAM avulsion at 3 months postpartum, assessed through transperineal pelvic-floor ultrasound. The primary safety endpoint was the incidence of adverse events (AEs) through 3 months postpartum.¹

Overall, 214 participants were randomized into the study, with 113 assigned to the Device group and 101 to the Control group. Among the Device group, 82 had the device placed, and 68 delivered vaginally. In the Control group, 85 delivered vaginally. At 3 months, ultrasound assessments were completed by 46 Device group participants and 64 Control group participants.¹

The study found no full LAM avulsions (0.0%) in the Device group compared to 10.9% in the Control group (p = 0.040). There was one serious maternal AE related to the device, but no serious neonatal AEs were device related. The results suggest that the IPD significantly reduces the incidence of complete LAM avulsion in nulliparous individuals undergoing first vaginal childbirth.¹

Additionally, the intrapartum electromechanical pelvic floor dilator demonstrated significant effectiveness in reducing the incidence of complete LAM avulsion during vaginal delivery in nulliparous women. The device was safe and well-received by participants, indicating its potential as a preventive measure for LAM avulsion and subsequent POP. Further studies with larger populations are warranted to confirm these findings and potentially incorporate the IPD into standard labor management protocols.¹

Materna is currently enrolling patients for its pivotal study to support a marketing submission of its Prep Device to the FDA.²

“Right now, there is no proven way to prevent this injury to the pelvic floor. We are hoping that by slowly pre-stretching the pelvic floor muscles before the start of pushing the baby out, we can significantly reduce the injuries that can lead to pelvic organ prolapse,” said Kara M. Rood, MD, maternal-fetal medicine specialist and EASE investigator. “The Materna Prep Device is the first device aiming to prevent pelvic muscle injury, so we’re excited to be publishing these results.”²

References:

1. Hesham H, Orejuela F, Rood KM, et al. Effect of an Intrapartum Pelvic Dilator Device on Levator Ani Muscle Avulsion During Primiparous Vaginal Delivery: A Pilot Randomized Controlled Trial. Int Urogynecol J. Published online August 3, 2024. doi:10.1007/s00192-024-05881-6

2. Materna Medical Announces Publication of EASE Pilot Study. Business Wire. August 6, 2024. Accessed August 6, 2024. https://www.businesswire.com/news/home/20240806398851/en/Materna-Medical-Announces-Publication-of-EASE-Pilot-Study