Prospective evaluation of the safety and feasibility of a pelvic floor dilator during active labor

The objective was to assess the safety and feasibility of using a pelvic floor dilator during active labor to prevent injuries to the levator ani muscle (LAM) and perineum. In a prospective pilot study, a pelvic floor dilator using soft pads was introduced into the vaginal canal to gradually expand the vagina, in 30 nulliparous women and in 10 controls. The primary outcomes were adverse events related to the device. Secondary outcomes were perineal lacerations after delivery, sonographically defined levator ani injury, hiatal area dimensions, and anal sphincter disruption, all at 12-20 weeks postpartum, and maximum pelvic floor dilation, time to achieve maximum dilation, and device retention rate. From October 2014 through November 2016, a total of 494 women were screened, and 61 consented to the study. Thirty women used the device and 27 returned for follow-up. No maternal or neonatal injuries were related to use of the dilator. The average maximum dilation of the vaginal canal was 7.4 cm (SD 0.7, range 5.5-8.0). Dilation time averaged 27 min (SD 13, range 5-60). Device insertion adjustment was needed in 13 out of 30 cases (43%). Similar rates of 3th-4th degree perineal lacerations were seen in both groups. Levator ani avulsion was diagnosed in 2 out of 27 (7%) in the device group and in 1 out of 9 (11%) in the control group (p = 0.2). The rate of partial injury in the device group was 2 out of 27 (7%) vs 2 out of 9 (22%) in the comparison group (p = 0.2). The use of the pelvic floor dilator during active labor is feasible. No safety issues were identified.