Does sonographic visual biofeedback before or during the second stage of labor improve outcomes? A meta-analysis

Effective pushing during the second stage of labor is critical for optimal birth outcomes, but many women-especially those under epidural analgesia-struggle with reduced pelvic sensation and pushing efficacy. Transperineal ultrasound is widely used to assess labor progression, and visual biofeedback has shown promise in improving physical and psychological outcomes in other fields. However, its application during labor remains underexplored.

This study assesses the effect of sonographic visual biofeedback before and during labor on obstetric outcomes.

We performed an electronic search using MEDLINE with the OvidSP interface PUBMED, Embase, Web of Science, and Cochrane Library up to August 13, 2024. We included experimental and non-experimental studies, comprising randomized controlled and observational (case-control, cohort, and cross-sectional) studies assessing the effect of sonographic visual biofeedback on delivery outcomes. Four references comprising 457 patients were eventually included. Primary data collection was performed using standardized data extraction procedures, with disagreements being settled by discussion. Analysis was conducted using RevMan 5.4 (Cochrane Collaboration, Oxford, UK).

Visual biofeedback is associated with a more pronounced change in angle of progression (AoP) measurements when comparing resting state to active pushing (mean difference [MD] 5.04 [95% confidence interval [CI] 1.42-8.66], P = 0.006, I² = 63%), and the overall AoP while pushing was notably greater in the visual feedback group (MD 9.23 [95% CI 0.94-17.53], P = 0.03, I² = 76%). There were no statistically significant differences in mode of delivery, duration of second stage of labor, rates of intact perineum, and incidence of second- and third-degree perineal tears. A significant reduction in episiotomies among patients who received visual feedback was observed (OR 0.42 [95%CI 0.24-0.76], P = 0.004, I² = 0%).

Visual feedback might influence maternal pushing behavior and enhance pushing efficacy, potentially reducing obstetrical interventions such as episiotomies. Additional prospective randomized studies are needed to definitively determine the effect of visual biofeedback on a wide range of obstetric outcomes. Such research could help refine the use of this technique and potentially improve the labor experience and outcomes for many women. The study protocol can be assessed at the PROSPERO International prospective register of systematic reviews (www.crd.york.ac.uk/PROSPERO, registration number CRD42024570484).