Objective: To review the literature and evaluate the role of the amniotic fluid index (AFI) on the success of an external cephalic version (ECV).
Study design: A computerized search of MEDLINE and Cochrane databases were conducted using 'breech', 'version', 'external cephalic version', 'amniotic fluid', and 'amniotic fluid index'. References from the identified publications were manually searched to identify additional relevant articles. Articles from 1987 to 2004 were included.
Results: Of the initial 33 articles discovered, only three remained after exclusions. These articles used different AFI ranges for 'borderline' or 'low-normal' fluid measurements and therefore could not be combined for analysis. All three studies demonstrated a lower success rate of ECV with lower amniotic fluid volume estimates (AFI 5-8, <10, or <8.6), although none reached statistical significance.
Conclusion: Due to limited and dissimilar data, it is impossible to define the lower AFI threshold for an unsuccessful ECV compared with the success of a normal AFI. Although not statistically significant, an AFI <10 may correlate with lower success rates for an ECV.