OC04.01: Does fundal pressure in the second stage (Kristeller manoeuvre) increase the risk of pelvic floor damage? A prospective case–control study

To investigate the effects of fundal pressure during the second stage of labour (Kristeller manoeuvre) on levator ani muscle (LAM) integrity through 3D transperineal ultrasound in primiparous women. Prospective case–control trial. Patients who underwent fundal pressure in the second stage of labour were recruited as “cases”. For every case a matched “control” patient with spontaneous vaginal delivery was enrolled. All patients were evaluated at least 3 months after vaginal delivery through a 3D/4D transperineal ultrasound performed by an operator blinded to the patient's history. Levator ani integrity was evaluated during maximum contraction while hiatal area was calculated at rest, during contraction and during Valsalva. We defined as “ballooning” a hiatal area greater than 25 cm2 during Valsalva. Overall, 94 cases and 82 controls underwent the postpartum transperineal ultrasound. No significant difference was demonstrated between the 2 groups as regards maternal age, BMI, gestational age at delivery, birthweight, epidural analgesia, second stage length, labour length, and symptoms of pelvic floor dysfunction while maternal weight was significantly higher in the Kristeller group. The incidence of LAM avulsion was significantly higher in women belonging to the Kristeller group (27/94; 28.7% vs 11/82; 13.4%, p = 0.014), while no significant difference was noted between hiatal areas in the two groups at rest, contraction and Valsalva, and no difference was noted on the incidence of hiatal ballooning. Kristeller manoeuvre is associated with an increased incidence of levator ani avulsion in primiparous women.