Surface electromyography of the pelvic floor at 6-8 weeks following delivery: a comparison of different modes of delivery.

The objective of this study was to compare the impact of different modes of delivery, especially forceps delivery (FD), on pelvic floor muscles (PFMs) through vaginal surface electromyography (sEMG) in primiparous women at early (6–8 weeks) postpartum. A total of 1259 primiparous women with full-term singleton births were included in this cross-sectional study. Of these, 98 were delivered by forceps, 865 underwent spontaneous vaginal delivery (SD) and 296 underwent elective cesarean delivery (CD). Clinical demographic characteristics and vaginal sEMG variables of parturients 6–8 weeks after birth were collected and analyzed using SPSS software. One-way ANOVA with Bonferroni correction, Chi-square test or Student’s t-test was used according to the variable type. Spearman correlation and binary logistic regression analyses were also used. P/α ≤ 0.05 was considered statistically significant. Amplitude of fast and sustained contractions on sEMG in the FD group was significantly lower compared with the CD and SD groups. The sEMG amplitude of all contractions was significantly higher in the CD group compared with the FD and SD groups (P < 0.01). According to binary logistic regression analysis, mode of delivery was a major influencing factor in sEMG. An early postpartum sEMG test appears to be helpful for the assessment of PFM activity. Mode of delivery was a major influencing factor on sEMG. Forceps delivery significantly inversely influenced PFM activity.