Pelvic Floor Muscle Electromyography in Natural Delivery: A Scoping Review

Vaginal delivery (VD) can induce neuromuscular changes in the pelvic floor muscles (PFMs), contributing to urinary and fecal incontinence. This scoping review maps and synthesizes the available evidence on the use of electromyography (EMG) to detect and characterize PFM alterations across the peripartum and postpartum periods, with attention to study designs, EMG acquisition protocols, reported EMG markers associated with childbirth, and research gaps. We searched Scopus, Web of Science, IEEE Xplore, PubMed, CINAHL, and Embase in early May 2026 using database-adapted strings. English-language studies employing EMG in women assessed before, during, or after childbirth were included. Results were synthesized narratively. From 1846 identified records, 51 studies were included. Evidence was highly heterogeneous in populations, timing, electrode/probe configurations, and signal processing/normalization, limiting comparability. Accordingly, the evidence is summarized descriptively. Nonetheless, amplitude-based measures tended to indicate lower recorded amplitude after VD than after cesarean section (CS) and, in some studies, in parous postpartum women compared with nulliparous controls, with possible partial recovery over time in selected cohorts; however, findings were not fully consistent and were influenced by assessment timing and methodology. Invasive EMG studies reported motor unit action potential characteristics and fiber-density findings consistent with denervation/reinnervation and neuromuscular remodeling. Emerging multichannel high-density intravaginal/intrarectal EMG has been explored in research settings, offering improved spatial resolution, which may help to better capture localized dysfunction. Standardized methodologies are needed to enhance clinical translation.