The force applied to successfully turn a foetus during reattempts of external cephalic version is substantially reduced when performed under spinal analgesia

Objective: To compare the forces exerted during external cephalic version (ECV) on the maternal abdomen between (1) the primary attempts performed without spinal analgesia (SA), which failed and (2) the subsequent reattempts performed under SA. Methods: Patients with an uncomplicated singleton breech-presenting pregnancy suitable for ECV were recruited. During ECV, the operator wore a pair of gloves, which had thin piezo-resistive pressure sensors measuring the contact pressure between the operator's hands and maternal abdomen. For patients who had failed ECV, reattempts by the same operator was made with patients under SA, and the applied force was measured in the same manner. The profile of the exerted forces over time during each attempt was analyzed and denoted by pressuretime integral (PTI: mmHg sec). Pain score was also graded by patients using visual analogue scale. Both PTI and pain score before and after the use of SA were then compared. Results: Overall, eight patients who had a failed ECV without SA underwent a reattempt with SA. All of them had successful version and the median PTI of the successful attempts under SA were lower than that of the previous failed attempts performed without SA (127 386 mmHg sec vs. 298,424 mmHg sec; p=0.017). All of them also reported a 0 pain score, which was significantly lower than that of before (median 7.5; p=0.016). Conclusions: SA improves the success rate of ECV as well as reduces the force required for successful version.