External cephalic version for breech presentation with or without spinal analgesia in nulliparous women at term: A randomized controlled trial

OBJECTIVE: To compare the success of external cephalic version using spinal analgesia with no analgesia among nulliparas. METHODS: A prospective randomized controlled trial was performed in a tertiary referral center delivery suite. Nulliparous women at term requesting external cephalic version for breech presentation were randomized to receive spinal analgesia (7.5 mg bupivacaine) or no analgesia before the external cephalic version. An experienced obstetrician performed the external cephalic version. Primary outcome was successful conversion to vertex presentation. RESULTS: Seventy-four women were enrolled, and 70 analyzed (36 spinal, 34 no analgesia). Successful external cephalic version occurred among 24 of 36 (66.7%) women randomized to receive spinal analgesia compared with 11 of 34 (32.4%) without, P=.004 (95% confidence interval [CI] of the difference: 0.0954-0.5513). External cephalic version with spinal analgesia resulted in a lower visual analog pain score, 1.76±2.74 compared with 6.84±3.08 without, P<.001. A secondary analysis logistic regression model demonstrated that the odds of external cephalic version success was 4.0-fold higher when performed with spinal analgesia P=.02 (95% CI, odds ratio [OR] 1.2-12.9). Complete breech presentation before attempting external cephalic version increased the odds of success 8.2-fold, P=.001 (95% CI, OR 2.2-30.3). Placental position, estimated fetal weight, and maternal weight did not contribute to the success rate when spinal analgesia was used. There were no cases of placental abruption or fetal distress. CONCLUSION: Administration of spinal analgesia significantly increases the success rate of external cephalic version among nulliparous women at term, which allows possible normal vaginal delivery. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00119184.