Impact of full vs empty urinary bladder on external cephalic version success: a randomized controlled trial.

Background: External cephalic version is a procedure used to turn a fetus from a breech position to a cephalic position before delivery. The success rate of the external cephalic version can be affected by various factors; however, the effect of bladder volume on the success rate of the external cephalic version remains controversial.
Objective: This study aimed to determine the effect of urinary bladder status (full or empty) on the success rate of the external cephalic version through a prospective randomized study.
Study Design: This was a prospective randomized controlled trial conducted at a tertiary care obstetrical center. Overall, 70 women with a singleton breech presentation at term undergoing external cephalic version were randomly allocated into 2 groups: external cephalic version with an empty bladder and external cephalic version with a full bladder. The external cephalic version procedure was performed by experienced obstetricians under ultrasound guidance. The primary outcome was the success rate of the external cephalic version.
Results: The success rate of the external cephalic version was 67.56% (25/37) in the full bladder group and 54.54% (18/33) in the empty bladder group, with no statistically significant difference between the groups (P=.26). In addition, the relative risk of successful external cephalic version was 1.23 (95% confidence interval, 0.84-1.81), indicating no significant difference.
Conclusion: This randomized controlled trial demonstrated that the presence of a full or empty urinary bladder does not significantly affect the success rate of the external cephalic version in women with singleton breech presentation at term. Our findings suggest that women undergoing an external cephalic version do not need to have a full bladder to improve the success rate of the procedure.
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