The Surface Electromyography of the Pelvic Floor Muscles in the Early Postpartum Period in Twin Pregnancies of Different Conception Modes: A Single-Centre Retrospective Study in China.

Purpose: To assess the early postpartum pelvic floor function in twin pregnancies of different conception modalities by measuring surface electromyography of the pelvic floor muscles with the Glazer protocol. Methods: This retrospective study analyzed 241 twin pregnancies delivered via cesarean section at the International Peace Maternity and Child Health Hospital (IPMCHH), affiliated with Shanghai Jiao Tong University School of Medicine, between March 2019 and December 2023. Participants underwent pelvic floor function assessments 42-60 days postpartum. Pelvic floor muscle activity was evaluated using surface electromyography (sEMG) following the Glazer protocol. Univariate and multivariable logistic regression analyses were performed to assess the impact of conception modes (natural vs ART) on early postpartum pelvic floor function in twin pregnancies. Results: The mean anterior resting phase amplitude was 4.80 ± 5.23 μV in the ART group versus 6.38 ± 6.30 μV in the naturally conceived group. Similarly, the posterior resting phase amplitude measured 5.15 ± 5.28 μV (ART) and 6.78 ± 7.67 μV (natural conception). The total Glazer score differed significantly between groups, with ART pregnancies scoring 74.80 ± 14.82 and natural conception pregnancies scoring 67.57 ± 21.57 (P < 0.05). Univariate and multivariable logistic regression analyses confirmed that the total Glazer score during the early postpartum period was independently associated with conception mode (P < 0.05). Conclusion: Women with twin pregnancies conceived via ART may exhibit marginally improved pelvic floor function during the early postpartum period (6-8 weeks) compared to naturally conceived counterparts, potentially attributable to elevated estrogen levels associated with ART.