Effect of Oral Hydration on External Cephalic Version at Term

Abstract

Objective: To evaluate the effect of oral hydration on the success rate of external cephalic version (ECV).

Design: Randomized controlled and single-blind trial.

Setting: Academic tertiary hospital with approximately 3,000 births annually.

Participants: One hundred sixty-four women at a gestational age of at least 37 weeks with breech-presenting fetuses and normal amniotic fluid indexes (AFIs).

Methods: Participants were randomly assigned to drink 2000 ml or no more than 100 ml of water in the 2 hours before undergoing ECV. The AFIs were assessed before and after treatment by the same sonographer, who was blinded to the treatment group. Data were collected on relevant maternal and fetal characteristics and ECV success.

Results: The mean AFI after hydration was significantly greater than that in the control group (15.5 cm vs. 13.4 cm, p = .003). The ECV success rate was 53.7% in the hydration group and 46.3% in the control group (odds ratio: 1.34, 95% confidence interval [0.69, 2.59]; p = .349). Hydration was well tolerated and there were no serious adverse events.

Conclusion: Oral hydration significantly increased the AFIs but did not affect the success rate of ECVs.

Keywords: amniotic fluid index; breech presentation; external cephalic version; external cephalic version success rate; maternal oral hydration.