Second stage labour duration and pelvic floor outcomes in primiparous women delivering macrosomic foetuses: a prospective study

BACKGROUND: To investigate the association between the duration of the second stage of labour (SSL) and early postpartum pelvic floor dysfunction (PFD) in primiparous women delivering macrosomic foetuses. METHODS: 200 eligible primiparous women were stratified by SSL duration into Group A (t ≥ 3h), Group B (2h ≤ t < 3h), and Group C (t < 2h). At six weeks postpartum, transperineal ultrasound was performed to determine bladder neck position and levator ani hiatus (LAH) area. Pelvic floor muscle (PFM) strength was evaluated using the Oxford scale, while PFM function was measured via vaginal pressure testing. The occurrences of stress urinary incontinence (SUI) and pelvic organ prolapse (POP) were recorded. RESULTS: < 0.05). CONCLUSION: A prolonged SSL (≥ 3 h) is associated with weaker PFM strength, greater muscle fatigue, enlarged levator hiatus, and a higher incidence of POP in primiparous women delivering macrosomic foetuses.