Patient characteristics associated with complications of external cephalic version

Patient characteristics associated with external cephalic version success are well documented; however, the association between patient characteristics and the likelihood of external cephalic version complications is poorly understood.

This study aimed to assess the frequency of patient characteristics associated with complications that lead to unanticipated delivery during external cephalic version.

This retrospective study included pregnant women aged at least 18 years with singleton gestations who underwent an external cephalic version attempt between 2006 and 2016 at a single quaternary care center. External cephalic version complications were defined as persistent nonreassuring fetal status, placental abruption, labor, spontaneous rupture of membranes, and umbilical cord prolapse. Complications were only considered if they led to unanticipated induction or cesarean delivery within 24 hours of external cephalic version. Patient characteristics including maternal age, height, weight, body mass index, parity, fetal sex, gestational age, estimated fetal weight, the type of fetal malpresentation, and placental location were analyzed for their association with external cephalic version complications using univariable analysis and multivariable logistic regressions.

Among the 1138 patients included in this analysis, external cephalic version complications occurred in 6.7% (n=76). These complications (not mutually exclusive) included nonreassuring fetal status (4.8%, n=55), placental abruption (1.6%, n=18), labor (1.0%, n=11), spontaneous rupture of membranes (0.6%, n=7), and cord prolapse (0.1%, n=1). Neonatal outcomes for those with complications included intensive care unit admission (10.5%, n=8), 5-minute Apgar scores <5 (1.3%, n=1), cord arterial pH <7 (6.6%, n=5), head cooling (1.3%, n=1), and anemia (6.6%, n=5). There were no perinatal deaths. In multivariable analysis, higher body mass index (adjusted odds ratio, 0.90 per kg/m²; 95% confidence interval, 0.84-0.97) and estimated fetal weight (adjusted odds ratio, 0.998 per gram; 95% confidence interval 0.998-0.999) were associated with decreased likelihood of experiencing external cephalic version complications, whereas greater gestational age at procedure (adjusted odds ratio, 1.95 per week; 95% confidence interval, 1.4-2.7) and anterior placental location (adjusted odds ratio, 2.0; 95% confidence interval, 1.1-3.7) were associated with increased likelihood of experiencing external cephalic version complications.

In this large series, complications that led to delivery during external cephalic version occurred in 6.7% patients and were associated with body mass index, estimated fetal weight, gestational age, and placental location.