Effects of external cephalic version for breech presentation at or near term in high-resource settings: A systematic review of randomized and non-randomized studies.

INTRODUCTION: External cephalic version (ECV) for breech presentation involves manual manipulation of the fetus from breech to cephalic presentation at or near term, in an attempt to avoid breech birth. This systematic review summarizes the literature on the effects of ECV at or near term on pregnancy outcomes in high-resource settings. METHODS: The MEDLINE, Embase, CINAHL, Cochrane Library, MIDIRS, and SweMED+ databases were searched for relevant articles published through April 2019, with no limitation on publication date. Clinical trials comparing the effects of ECV at ≥36 weeks, with or without tocolysis, with that of no ECV, conducted in northern, western, and central Europe, the USA, Canada, Australia, and New Zealand were eligible for inclusion. RESULTS: Nine articles reporting on 184704 breech pregnancies were included. Pooled data showed that ECV attempts reduced the failure to achieve vaginal cephalic birth (risk ratio, RR=0.56; 95% CI: 0.45-0.71), caesarean section performance (RR=0.57; 95% CI: 0.50-0.64), and non-cephalic presentation at birth (RR=0.45; 95% CI: 0.29-0.68) compared with no ECV. ECV attempts also increased the incidence of Apgar score <7 at 5 minutes (RR=1.29; 95% CI: 1.10-1.52). CONCLUSIONS: Women for whom ECV is attempted at or near term are at reduced risk of caesarean section, non-cephalic presentation at term, and failure to achieve vaginal cephalic birth. Compared with no ECV, attempted ECV was also associated with a slightly increased risk of a low Apgar score at 5 minutes. The evidence is limited by the scarcity of high-quality research and the presence of risks of bias.