Effect of ultrasound‐guided visual biofeedback performed by midwives on duration of second stage of labor: randomized controlled trial

Abstract

ABSTRACT Objective To investigate whether coached maternal pushing using transperineal ultrasound (TPUS)‐guided visual biofeedback, performed by midwives, reduces the duration of the second stage of labor and affects the mode of delivery in nulliparous women receiving epidural analgesia. Methods This was a single‐center randomized controlled trial of nulliparous women with a singleton term pregnancy with an estimated fetal weight of 2500–4000 g, who were in the active stage of labor and were receiving epidural analgesia, conducted between May 2021 and August 2024. Consenting participants were assigned randomly to one of two groups: the study group (sonographic‐coaching group), who were coached using TPUS‐guided visual biofeedback, or the control group (traditional‐coaching group), who were coached using the traditional vaginal technique. Coached maternal pushing with TPUS‐guided visual biofeedback included a demonstration of the direction of effective pushing by visualizing the real‐time downward movement of the fetal head on a television screen in front of the woman. Coaching sessions were conducted following epidural administration during the active stage of labor and after the diagnosis of complete cervical dilatation, with an additional session conducted if delivery had not occurred within 2 h after complete cervical dilatation. Coaching was led exclusively by midwives, with no involvement of obstetricians. Outcomes were compared between the groups. Results A total of 327 women were randomized and included, comprising 168 women in the sonographic‐coaching group and 159 in the traditional‐coaching group. Demographic and baseline characteristics, including maternal body mass index and rates of labor induction and oxytocin use, were similar in both groups. The second stage of labor was significantly shorter in the sonographic‐coaching group compared with the traditional‐coaching group (mean ± SD, 107 ± 59 min vs 132 ± 71 min; P = 0.001). The sonographic‐coaching group also showed lower rates of second‐degree or higher perineal tears (65.4% vs 77.3%; P = 0.020) and intrapartum fever (8.9% vs 16.4%; P = 0.043). Other secondary outcomes, including neonatal birth weight and 5‐min Apgar score, did not differ significantly between the groups. No significant differences were observed in the mode of delivery. Conclusions Coached maternal pushing using TPUS‐guided visual biofeedback, performed by midwives, significantly reduced the duration of the second stage of labor and the incidence of second‐degree or higher perineal tears and intrapartum fever. Larger studies are warranted to further assess its impact on delivery outcome. © 2026 International Society of Ultrasound in Obstetrics and Gynecology.