Comparisons of Electromyography and Digital Palpation Measurement of Pelvic Floor Muscle Strength in Postpartum Women with Stress Urinary Incontinence and Asymptomatic Parturients: A Cross-Sectional Study

Aims: Early evaluation of pelvic floor muscle (PFM) in postpartum women is important for the treatment of stress urinary incontinence (SUI). Digital vaginal palpation and electromyography (EMG) evaluation based on Glazer protocol are widely used for the assessment of PFM. However, the correlation among digital palpation, EMG, and morbidity of postpartum SUI is still unclear. This study aims to investigate the relationship between postpartum SUI and PFM examinations. Methods: This hospital-based cross-sectional study included 1,380 parturients during September 2016 to January 2018. We collected the clinical characteristics, PFM strength, and EMG variables of parturients 6-8 weeks after birth. Then the correlation among the results of EMG, digital palpation, and the occurrence of SUI was analyzed. Results: There is no significant difference in digital palpation scores of PFM strength between SUI and non-SUI parturients. The EMG values were closely related to SUI: the multivariate logistic regression revealed that the most reliable evaluation indicators of postpartum SUI were pelvic floor contractile amplitude of endurance contraction (B = 0.021, p = 0.019) and pretest resting baseline (B = 0.056, p = 0.019). Correlation analysis demonstrated that the contraction variables of EMG had a significant correlation with the digital palpation PFM strength in postpartum women (r = 0.467-0.545, p < 0.001). Conclusion: The EMG proved to be reliable in assessing the PFM function in postpartum women. The decreased PFM activity, according to EMG, was correlated with postpartum SUI. Although digital palpation scores were positively correlated with EMG results, no correlation was observed with SUI incidence.