Fetal malpresentation is the third most common indication for primary cesarean delivery (ACOG) (1). As external cephalic version (ECV) has a success rate of about 50 percent (2), offering this procedure in cases of breech presentation at term is one of the ways to reduce the risk of cesarean delivery, with the associated risk of morbidity and mortality for women (1). Although most women with a successful ECV deliver vaginally (3), the procedure is underutilized: recent studies have shown that among cases of breech presentation at 36 weeks, an ECV was attempted in only 46 percent of them (3), and among breech deliveries at 40 hospitals in the Netherlands, ECV had not been attempted in 38 percent of cases without contraindications (4). The rate of implementation of ECV may vary widely within the same country (from 8 to 84% in the Netherlands) (4) and the success of the procedure seems to be operator-dependent (5).Although several studies have been published on predictors of success of ECV and procedure-related complications (2), little has been written on the technique itself of ECV. The opportunity to learn ECV during training is often limited, and obstetricians and midwives who would like to perform the procedure may not feel adequately prepared to do it. The perception that ECV requires physical strength further limits its use. External cephalic version is a gentle art (6), and we would like to share some tricks of the trade from our experience of more than 20 years of performing this procedure. Most of the suggestions that follow are designed to limit the complications of ECV and increase the likelihood of success.
TimingWe recommend performance of ECV at 36-37 weeks of gestation at the earliest. This allows the breech fetus ample time to turn into the cephalic position spontaneously while avoiding the risks of prematurity in case ECV results in preterm birth (2). After 36 weeks, spontaneous version of a breech fetus is unlikely. There is no upper gestational age limit for ECV; we have successfully performed ECV on fetuses as large as 4 kg in patients who were at 40 weeks in early labor.
Maternal characteristicsThere is no general consensus on eligibility of women for ECV (7). Maternal weight (and weight distribution) has been in our experience an important determinant of success. Although no individual body mass index cutoff can be used as contraindication for ECV, difficulty in identifying fetal parts as a result of central obesity makes ECV difficult to perform. Some experts quote uterine anomalies as contraindications for ECV (8), but decisions should probably be individualized: a bicornuate uterus in which the fetus was cephalic until 36 weeks and then turns to breech may not be an absolute contraindication. Some variables, such as history of previous uterine scars or placental abruption, are considered contraindications to ECV by some, mainly because the evidence of the safety of ECV in these contexts is limited (2,7). However, limited data on the safety of the procedure in these settings should not be i...