Success rate and influencing factors of external cephalic version for breech presentation / 中华围产医学杂志

ABSTRACT

Objective To discuss the success rate of external cephalic version (ECV) for breech presentation in singleton pregnancies and the factors influencing ECV,and complications induced by ECV.Methods A prospective study was conducted which included 204 pregnant women who underwent regular prenatal examinations and delivered in Nanjing Drum Tower Hospital between March 1,2011 and February 29,2012.The 204 cases were single pregnancy with breech presentation identified by ultrasound during 32-37+6 weeks of gestation,and without other indications for cesarean section (CS).According to willingness of the participants,204 cases were divided into two groups.The 101 pregnant women who refused EVC (control group) were asked to practice knee-chest position twice a day; and 103 pregnant women volunteered to undergo EVC (ECV group) during 32-37+6 weeks of gestation.The proportion of cephalic presentation at delivery,CS rate and the incidence of PROM,premature delivery and cord around the neck were compared between the two groups.Factors influencing the success rate of ECV were analyzed.Chi-square or adjusted Chi-square test were used for statistical analysis.Results The proportion of cephalic presentation at delivery in the ECV group was higher than that in the control group [68.9％ (71/103) vs 29.7％ (30/101),x2=31.39]; the CS rate in the ECV group was lower than that in the control group [49.5％ (51/103) vs 78.2％ (79/101),x2=18.18],as was the rate of CS due to breech presentation [62.7％ (32/51) vs 89.9％ (71/79),x2=13.86],all P＜0.05.The success rates in frank breech presentation,complete breech presentation and incomplete breech presentation were 77.1％ (37/48),72.7％ (24/33) and 45.5％ (10/22),respectively (x2=7.37,P＜0.05),and the success rate in frank breech presentation was higher than that in incomplete breech presentation (x2=6.84,P＜0.017).No significant differences were observed in the success rates between primiparas and multiparas [67.7％ (63/93) vs 8/10,x2=0.19],placenta attached at front wall of uterus and other attachment sites [61.0％ (25/41) vs 74.2％ (46/62),x2=2.01],and EVC performed at 32-35+6weeks of gestation and 36-37+6 weeks [70.5％ (62/88) vs 9/15,x2=0.65],allP＞0.05.No significant differences were observed for the incidence of PROM [7.8％ (8/103) vs 6.9％ (7/101)],premature delivery [2.9％ (3/103) vs 2.0％ (2/101)] and cord around the neck [17.5％ (18/103) vs 21.8％ (22/101)] between the ECV and control group (x2=0.05,0.19 and 0.60,all P＞0.05).Conclusions ECV for breech presentation in singleton pregnancies can effectively correct the fetal position and reduce the CS rate.ECV performed after 32 weeks of gestation does not increase the risk of PROM and premature delivery.