Ultrasound imaging in prolonged second stage of labor: does it reduce the operative delivery rate?

Abstract

Objective: To reduce the operative delivery rate in the prolonged second stage of labor (PSSL) through intrapartum sonography.

Methods: Sixty-two women – with uncomplicated pregnancies at term, fetus in cephalic presentation and occipitoanterior position, in PSSL – had already undergone epidural anesthesia and oxytocin infusion. Transperineal ultrasound was performed to define fetal head direction (downward, horizontal, and upward) and patients were divided into three groups (D, H, and U).

Proposed protocol: Cessation of oxytocin infusion, addition of a dose of anesthesia, invitation to assume a hand-and-knee position, and to relax. After one hour, oxytocin infusion was started again and women were invited to push. Fetal well-being ensured by cardiotocography (CTG). Chi-square test was used to compare the mode of delivery: cesarean section (CS), vacuum extraction (VE), and spontaneous delivery (SD).

Results: Group D (n = 20): 4 SD (20%), 4 VE, 12 CS; group H (n = 22): 9 SD (41%), 9 VE, 4 CS; group U (n20): 16 SD (80%), 4 VE. The risk of not having a SD in group D versus U is quadrupled (RR 4; 95% CI 1.6–9.9).

Conclusions: Ultrasound diagnosis of fetal head upward direction is highly predictive of SD in case of PSSL. Further studies are needed to assess this hypothesis.

• Hand and knee position
• oxytocin
• spontaneous delivery
• transperineal ultrasound

Acknowledgements

The authors wish to thank Laura Bergamasco, Full Professor at the Department of Physics at Turin University, for the precious work regarding statistical analysis, and Dr. Lorella Vesentini for the enthusiastic cooperation regarding drawing Figures 1 and 2.