OBSTETRICS
Mode of Delivery Following Successful External Cephalic Version: Comparison With Spontaneous Cephalic Presentations at Delivery Simone M. I. Kuppens, MD, PhD,1 Eileen K. Hutton, RN, RM, PhD,2,3 Tom H. M. Hasaart, MD, PhD,1 Nassira Aichi, MD,1 Henrica A. Wijnen, PhD,4 Victor J. M. Pop, MD, PhD5 1
Department of Obstetrics and Gynaecology, Catharina Hospital, Eindhoven, the Netherlands
2
Department of Obstetrics and Gynaecology, McMaster University, Hamilton ON
3
Department of Midwifery Science VU Medical Center, Amsterdam, the Netherlands
4
Department of Midwifery Science, Zuyd University, Maastricht, the Netherlands
5
Department of Medical Health Psychology, University of Tilburg, Tilburg, the Netherlands
Abstract
Résumé
Objective: To compare the obstetric outcomes of pregnant women after successful external cephalic version (ECV) (cases) with a large group of pregnant women with a spontaneously occurring cephalic fetal position at delivery (controls).
Objectif : Comparer les issues obstétricales que connaissent des femmes enceintes à la suite de la réussite d’une version céphalique par manœuvres externes (VCE) (cas) à celles que connaissent un important groupe de femmes enceintes qui présentent un fœtus se trouvant spontanément en position céphalique au moment de l’accouchement (témoins).
Methods: We conducted a retrospective matched cohort study in a teaching hospital in the Netherlands. Delivery outcomes of women with a successful ECV were compared with those of women with spontaneously occurring cephalic presentations, controlling for maternal age, parity, gestational age at delivery, and onset of labour (spontaneous or induced). Exclusion criteria were a history of Caesarean section, delivery at < 35 weeks, and elective Caesarean section. The primary outcome was the prevalence of Caesarean section and instrumental delivery in both groups; secondary outcomes were the characteristics of cases requiring intervention such as Caesarean section or instrumental delivery. Results: Women who had a successful ECV had a significantly higher Caesarean section rate than the women in the control group (33/220 [15%] vs. 62/1030 [6.0 %]; P < 0.001). There was no difference in the incidence of instrumental delivery (20/220 [9.1%] vs. 103/1030 [10%]). Comparison of characteristics of women in the cases group showed that nulliparity, induction of labour, and occiput posterior presentation were associated with Caesarean section and instrumental deliveries. Conclusion: Compared with delivery of spontaneous cephalic presenta tions, delivery of cephalic presenting babies following successful ECV is associated with an increased rate of Caesarean section, especially in nulliparous women and women whose labour is induced. J Obstet Gynaecol Can 2013;35(10):883–888 Key Words: External cephalic version, breech presentation, Caesarean section, instrumental delivery Competing Interests: None declared. Received on December 1, 2012 Accepted on July 22, 2013
Méthodes : Nous avons mené une étude de cohorte appariée rétrospective au sein d’un hôpital universitaire des Pays-Bas. Nous avons comparé les issues de l’accouchement chez des femmes ayant subi une VCE réussie à celles de femmes ayant connu une présentation céphalique spontanée, tout en nous assurant de neutraliser les effets de l’âge maternel, de la parité, de l’âge gestationnel au moment de l’accouchement et de la nature de l’apparition du travail (spontané ou déclenchement). Parmi les critères d’exclusion, on trouvait les antécédents de césarienne, l’accouchement à < 35 semaines et la césarienne de convenance. Le critère d’évaluation principal était la prévalence de la césarienne et de l’accouchement instrumental dans les deux groupes; les critères d’évaluation secondaires étaient les caractéristiques des cas nécessitant une intervention (comme une césarienne ou un accouchement instrumental). Résultats : Les femmes ayant subi une VCE réussie ont présenté un taux de césarienne considérément plus élevé que celui des femmes du groupe « témoins » (33/220 [15 %] vs 62/1 030 [6,0 %]; P < 0,001). Aucune différence n’a été constatée en ce qui concerne l’incidence de l’accouchement instrumental (20/220 [9,1 %] vs 103/1 030 [10 %]). La comparaison des caractéristiques des femmes du groupe « cas » a révélé que la nulliparité, le déclenchement du travail et la présentation occipito-postérieure étaient associés aux accouchements par césarienne et instrumentaux. Conclusion : Par comparaison avec l’accouchement de fœtus en présentation céphalique spontanée, l’accouchement de fœtus adoptant une position céphalique à la suite d’une VCE réussie est associé à une hausse du taux de césarienne, particulièrement chez les nullipares et les femmes qui subissent un déclenchement du travail.
OCTOBER JOGC OCTOBRE 2013 l 883
Obstetrics
INTRODUCTION
P
erforming external cephalic version (ECV) is the best means of reducing the number of breech presentations and breech deliveries at term, and is recommended by the American Congress of Obstetricians and Gynecologists and the Royal College of Obstetricians and Gynaecologists.1–3 It is clear that ECV reduces the incidence of Caesarean section in women with a breech presentation.1 However, whether successful ECV affects the mode of delivery remains uncertain. Some studies have shown that Caesarean section and instrumental delivery rates are not increased after successful ECV,4–7 whereas other studies show the opposite.8–13 These different outcomes can be explained by differences between studies such as sample size, ethnic differences, and different proportions of nulliparous and multiparous patients (Table 1). Maternal age, parity, gestational age at delivery, and type of onset of labour (spontaneous or induced) are important determinants of mode of delivery that must be taken into account in such comparisons. Only one study, in 2009, matched study groups for all four of these variables and found that neither CS nor instrumental delivery rates were increased following successful ECV.7 However, a meta-analysis in 2004 showed a doubling of the incidence of intrapartum CS after successful version.14 These authors concluded that pregnancies after successful ECV should not be considered as normal pregnancies, and that these women should deliver in units where facilities for emergency CS and neonatal resuscitation are immediately available. With regard to our country (the Netherlands), this is an important issue because cephalic-presenting pregnancies after successful ECV are regarded as low-risk pregnancies and are referred back to primary midwifery care. We therefore performed a study comparing the obstetric outcomes of pregnant women who had a cephalic fetal position at delivery after successful ECV with a large group of pregnant women in which no ECV was performed and who presented with a spontaneously occurring cephalic fetal position at delivery. The primary outcome was the prevalence of CS and instrumental delivery in both groups. In a separate analysis we studied the characteristics of patients who had a CS or instrumental delivery after successful ECV. METHODS
We performed the study at the Catharina Hospital in Eindhoven, an academically affiliated, community-based hospital in the South East of the Netherlands. Data for the cases in this study were prospectively collected between 2007 and 2011 at the outpatient ECV clinic, where women were prospectively followed after an ECV attempt until 884 l OCTOBER JOGC OCTOBRE 2013
delivery. All women had a low-risk pregnancy without medical problems. After successful ECV, women were referred back to primary midwifery care. The ECV protocol used has been described in detail elsewhere.15 All the ECVs in our study were performed by the same two obstetricians working in unison. Only women who had a successful ECV and who presented with a cephalic position at delivery were included. The outcome of the ECV cohort was compared with a large control group of 1129 pregnant women drawn from the general population in the same area. Data from the control group were also prospectively collected as part of an observational study that was performed in low-risk women under primary midwifery care in the same area.16 From that study, women with a spontaneous cephalic position at delivery and in a gestational age range similar to the ECV group were used for comparison with the outcome of the ECV group. Exclusion criteria were patients with a previous history of CS, delivery < 35 weeks, and those who underwent a primary CS. This resulted in 220 women in the ECV group and 1030 women in the control group. The following obstetric parameters were defined. First, the start of labour was defined as spontaneous versus induced. In the latter, both patients with mechanical rupture of membranes and patients with medically induced labour were included. Second, the mode of delivery was defined as spontaneous vaginal delivery, instrumental delivery, and secondary CS. Possible differences between the cases and control subjects with regard to these parameters were compared. Nonprogressive labour was defined as lack of cervical dilatation over two to four hours despite adequate uterine contractions. Statistical analysis was performed using SPSS Version 19.0 (IBM Corp., Armonk NY). We performed t tests (two-tailed) and chi-square tests (and Fisher exact tests when appropriate) to compare obstetric characteristics and birth outcomes between the two groups. Finally, within the ECV group we compared the characteristics of those who had a spontaneous vaginal delivery versus those who needed intervention such as CS or instrumental delivery. The study was approved by the Medical Ethics Committee of the Catharina Hospital in Eindhoven, the Netherlands. RESULTS
From January 2007 to January 2011, ECV was performed on 438 women, of whom 280 (64%) were nulliparous. In 259/438 women (59%) ECV was successful. The mean gestational age at version was 36+1 weeks (SD 1 day) with a range of 35+4 weeks to 41+0 weeks. The mean interval from version to delivery was 4+0 weeks (SD 1.5 weeks) with a range of one day to 7+3 weeks.
Mode of Delivery Following Successful External Cephalic Version: Comparison With Spontaneous Cephalic Presentations at Delivery
Table 1. Reports of Caesarean section after successful ECV Authors Year of publication
Matching criteria
Sample size
Findings
Egge et al. 19944
Parity Gestational age at delivery Date of delivery
Cases 76 Control subjects 76
No significant difference in the CS rate between cases and control subjects (8% vs. 6%)
Laros et al. 19958
No matching
Cases 174
CS rate is higher in ECV group (31% vs. 15%) Reasons: failed induction and failed progress of labour
Lau et al. 19979
Age Parity Onset of labour
Cases 154 Control subjects 308
CS rate is higher in ECV group (16.9% vs. 7.5%, P < 0.005)
Siddiqui et al. 19995
No matching
Cases 92 Control subjects 184
No significant difference in the CS rate between study patients and control patients (22.8% vs. 23.4%)
Wax et al. 20006
Gestational age at delivery Labour onset Prior vaginal delivery Cervical dilatation on admission
Cases 38 Control subjects 114
No significant difference in the CS rate between cases and control subjects (3/38 vs. 1/114). No significant instrumental delivery rate (4/38 vs. 8/114) No increase in oxytocin use or labour duration
Chan et al. 200210
No matching
Cases 279 Control subjects 28447
CS rate is higher in ECV group (23.3% vs. 9.4%, aOR 3.6, CI 2.4 to 5.3) Instrumental delivery is higher in ECV group (14.3% vs. 12.8%, aOR 1.7, CI 1.1 to 2.4) Labour by induction is higher in ECV group (24% vs. 13.4%, OR 2.0, CI 1.5 to 2.7) Reasons: more fetal distress, more failure to progress, more failed induction More cases requiring epidural anaesthesia and surgical augmentation
Ben-Haroush et al. 200211
Age Gravidity Parity Ethnicity
Cases 96 Control subjects 192
CS rate is higher in ECV group (19.8% vs. 6.25%) Reasons: more failure to progress and malpresentation No difference in instrumental deliveries
Vézina et al. 200412
Parity
Cases 301 Control subjects 301
More CS in cases: 25.1% vs. 10.5% (P < 0.001) Nulliparous OR 2.04; 95% CI 1.13 to 3.68 Multiparous OR 4.30 95% CI 1.76 to 10.54 Reasons: more labour dystocia In multiparous more instrumental deliveries in cases (8.7% vs. 2.7%, P = 0.02). In multiparous also more suspected fetal distress
Clock et al. 20097
Parity Prior CS Gestatational age at delivery Labour onset
Cases 197 Control subjects 394
CS was not significant between the groups (16.8% vs. 11.9%)
Jain et al. 201013
No matching
Cases 93 Control subjects 103
More CS in cases: 18.2% vs. 7.7% (P < 0.028) No difference in rate of instrumental deliveries.
Because we performed primary CS in four cases and had missing data on delivery in 35 women, we excluded them from the study. The remaining 220 women were compared with 1030 women from a control group of 1129 who presented with a spontaneous cephalic position at delivery. The characteristics of the 220 cases and 1030 control subjects are shown in Table 2. The baseline characteristics were similar between the study and the control populations with respect to maternal age, gestational age at delivery, birth weight, and sex of the newborn, as well as the number of neonates with low
Apgar scores after five minutes. There were significantly more primiparous women in the ECV group. Labour characteristics and differences between the version and the control group are shown in Table 3. The CS rate was significantly (2.5 times) higher for women who presented with cephalic position after successful ECV than for control subjects (33/220 [15%] vs. 62/1030 [6%]; P < 0.001). There was no difference in the incidence of instrumental delivery between version and control group. Indications for CS such as dystocia in the first stage of labour, dystocia in the second stage of labour, or fetal distress were similar for the study and the control groups. OCTOBER JOGC OCTOBRE 2013 l 885
Obstetrics
Table 2. Characteristics of the study population Cases n = 220
Control subjects n = 1030
P
31.2 (3.9)
30.5 (3.6)
0.89*
21 to 40
22 to 41
0
121 (55)
484 (47)
≥1
99 (45)
546 (53)
40.1 (1)
40 (1.3)
35.4 to 43
35.4 to 42.9
Maternal age, years Mean (SD) Range Parity, n (%) 0.031†
Gestational age at delivery, weeks Mean (SD) Range
0.18*
Birth weight, grams Mean (SD)
3443 (465)
3519 (489)
1765 to 4650
1975 to 4972
Male
110 (50)
554 (54)
Female
110 (50)
476 (46)
2 (0.9)
11 (1.1)
Range
0.09*
Sex of the neonate, n (%)
Apgar 5 min < 7, n (%)
0.31† 0.83†
*t test †χ2 test
Table 3. Labour and delivery outcome of the study population ECV n = 220 n (%)
Control subjects n = 1030 n (%)
Onset of labour
0.58
Spontaneous
183 (83)
872 (85)
Induction
37 (17)
158 (15)
167 (76)
865 (84)
Operative vaginal
20 (9)
103 (10)
Caesarean section
33 (15)
62 (6)
Delivery outcome Spontaneous vaginal
Reasons for operative vaginal delivery
< 0.001
n = 20
n = 103
Fetal distress
9 (45)
41 (40)
Dystocia in second stage
11 (55)
62 (60)
Reasons for Caesarean section
n = 33
n = 62
Fetal distress
14 (42)
21 (34)
Dystocia in first stage
10 (30)
27 (44)
Dystocia in second stage
9 (28)
14 (22)
Occiput anterior
205 (93)
952 (92)
Occiput posterior
15 (7)
78 (8)
Cephalic presentation
886 l OCTOBER JOGC OCTOBRE 2013
P (χ2 test)
0.41
0.45
0.70
Mode of Delivery Following Successful External Cephalic Version: Comparison With Spontaneous Cephalic Presentations at Delivery
Table 4. Comparison of characteristics of vaginal deliveries and instrumental deliveries or Caesarean sections within the group of women with a successful ECV (N = 220) Vaginal deliveries n = 167
Caesarean sections and instrumental deliveries n = 53
Maternal age, years Mean (SD)
31 (4.4)
30.4 (6.0)
Range
22 to 40
20 to 39
0
74 (44.3)
47 (88.7)
≥1
93 (55.7)
6 (11.3)
Parity, n (%)
< 0.001†
Time interval from ECV to delivery, weeks
0.38*
Mean (SD)
4.0 (1.4)
4.2 (1.6)
Range
0 to 7.3
0 to 6.7
39+6 (3.3)
40+3 (1.3)
35+5 to 43+0
35+1 to 42+4
3398 (520)
3525 (507)
2120 to 4650
1950 to 4515
Gestational age at delivery, weeks+days Mean (SD) Range
0.33*
Birth weight Mean (SD) Range
P 0.41*
0.12*
Sex of the neonate, n (%)
0.15†
Male
79 (47)
31 (58)
Female
88 (53)
22 (42)
0 ( 0)
2 (4)
Apgar 5 min < 7, n (%) Onset of labour, n (%)
0.06† 0.003†
Spontaneous
146 (87.4)
37 (69.8)
Induction
21 (12.6)
16 (30.2)
Occiput anterior
164 (98)
41 (77)
Occiput posterior
3 (2)
12 (23)
Presentation of head position, n (%)
< 0.001†
*t test †χ2 test
When stratified for parity, the CS rate for nulliparous women in the version group was 29/121 (24%) compared with 48/484 (10%) in the control group (P < 0.001). In multiparous women, the CS rate in the version group was not statistically different from the control group (4/99 [4%] vs. 17/546 [3.2%]; P = 0.64). When stratified for induced onset of labour, the CS rate in the version group was 14/37 (38%) compared with 8/158 (5%) in the control group (P < 0.001). Comparison of characteristics of women in the version group showed that nulliparity, induction of labour, and occiput posterior presentation were associated with Caesarean section and instrumental delivery (Table 4). DISCUSSION
We found that ECV resulting in a cephalic position at delivery is associated with a higher risk of CS than in women
with a spontaneous cephalic position at delivery, while the incidence of instrumental delivery is not increased. This is in agreement with several other studies.8–13 However, four previous studies showed no increased risk of CS after successful ECV.4–7 Three of those studies had low sample size.4–6 However, the fourth study, published in 2009, did have an appropriate sample size (197 cases) and matched women undergoing ECV with a control group with respect to parity, gestational age at delivery, onset of labour, and maternal age.7 The difference between that study (by Clock et al.) and ours is that the study population of Clock et al. consisted of only 38% nulliparous patients, compared with 55% in our study. Furthermore, the CS rate in the study of Clock et al. was lower than expected and therefore a type 2 error could not be excluded. In our study, a post hoc analysis showed that the power of our study was 89% when accepting a type 1 error of 0.05. OCTOBER JOGC OCTOBRE 2013 l 887
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Nulliparity, induction of labour, and occiput posterior presentation are risk factors for CS after successful ECV. These factors have also been reported for the general popu lation, but are especially true for labour after ECV.10,12,17–19
REFERENCES 1. Hofmeyr GJ, Kulier R. External cephalic version for breech presentation at term. Cochrane Database Syst Rev 2012;10:CD000083.
The higher reported incidence of intrapartum CS following successful ECV has been attributed to labour dystocia and fetal distress.10–14 In our study, labour dystocia accounted for 19/33 (58%) of deliveries by CS and fetal distress for 14/33 (42%). The explanation could be that the underlying pathophysiology of breech presentation is partly similar to that of obstructive labour. Furthermore, fetuses in a breech position are more susceptible to the burden of the physical stress of labour than their cephalic counterparts.10,14
2. American College of Obstetricians and Gynaecologists (ACOG). External cephalic version. ACOG Practice Bull 2000; Number 13.
Several authors have recommended that labour after successful ECV warrants careful monitoring and should be considered to be high risk,9,10,14 in which case these patients will be need to be referred to an obstetrician for care. However, from Table 3 it can be seen that there is still a good chance of spontaneous vaginal birth after successful ECV. Therefore we conclude that women may keep their choice of place of delivery and care provider after successful ECV. However, they should be informed, and should take into consideration, that there is an increased risk of abnormal labour resulting in CS in nulliparous women and women whose labour is induced after ECV.
6. Wax JR, Sutula K, Lerer T, Steinfeld JD, Ingardia CJ. Labor and delivery following successful external cephalic version. Am J Perinatol 2000;17:183–6.
A limitation of our study is that we did not include BMI, oxytocin use, rates of epidural analgesia, and fetal surveillance in labour in our analysis. Furthermore, there were more nulliparous women in the ECV group than in the control group. The strength of our study is that the data were all collected prospectively and constitute the third largest sample to be published to date (after Vezina et al.12 and Chan et al.10). It contains a high proportion of nulliparous women (55%), who have the highest incidence of breech presentation towards term of all parity groups. We were able to compare our ECV group with a large sample of pregnant women from the same area. Finally, all the ECVs in our study were performed by the same two obstetricians, resulting in a low potential for inter-assessor variability. CONCLUSION
Although overall CS rates were below 15%, we found that delivery after successful ECV is associated with a 2.5 times higher rate of CS in comparison with spontaneous cephalic presentations. Women, particularly those who are nulliparous and whose labour is induced, should be informed about this increased risk, and care providers should take this into consideration when recommending where these women should give birth.
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3. Royal College of Obstetricians and Gynecologists (RCOG). The national sentinel caesarean section audit report. London: RCOG Press; 2001. 4. Egge T, Schauberger C, Schaper A. Dysfunctional labor after external cephalic version. Obstet Gynecol 1994;83:771–3. 5. Siddiqui D, Stiller RJ, Collins J, Laifer SA. Pregnancy outcome after successful external cephalic version. Am J Obstet Gynecol 1999;181:1092–5.
7. Clock C, Kurtzman J, White J, Chung JH. Cesarean risk after successful external cephalic version: a matched, retrospective analysis. J Perinatol 2009;29:96–100. 8. Laros RK Jr, Flanagan TA, Kilpatrick SJ. Management of term breech presentation: a protocol of external cephalic version and selective trial of labor. Am J Obstet Gynecol 1995;172:1916–25. 9. Lau TK, Lo KW, Rogers M. Pregnancy outcome after successful external cephalic version for breech presentation at term. Am J Obstet Gynecol 1997;176:218–23. 10. Chan LY, Leung TY, Fok WY, Chan LW, Lau TK. High incidence of obstetric interventions after successful external cephalic version. BJOG 2002;109:627–31. 11. Ben-Haroush A, Perri T, Bar J, Yogev Y, Bar-Hava I, Hod M, et al. Mode of delivery following successful external cephalic version. Am J Perinatol 2002;19:355–60. 12. Vézina Y, Bujold E, Varin J, Marquette GP, Boucher M. Cesarean delivery after successful external cephalic version of breech presentation at term: a comparative study. Am J Obstet Gynecol 2004;190:763–8. 13. Jain S, Mulligama C, Tagwira V, Guyer C, Cheong Y. Labour outcome of women with successful external cephalic version: a prospective study. J Obstet Gynaecol 2010;30:13–6. 14. Chan LY, Tang JL, Tsoi KF, Fok WY, Chan LW, Lau TK. Intrapartum cesarean delivery after successful external cephalic version: a metaanalysis. Obstet Gynecol 2004;104:155–60. 15. Kuppens SM, Waerenburgh ER, Kooistra L, van der Donk RW, Hasaart TH, Pop VJ. The relation between umbilical cord characteristics and the outcome of external cephalic version. Early Hum Dev 2011;87:369–72. 16. Rayman MP, Wijnen H, Vader H, Kooistra L, Pop V. Maternal selenium status during early gestation and risk for preterm birth. CMAJ 2011;183:549–55. 17. Dahlen HG, Tracy S, Tracy M, Bisits A, Brown C, Thornton C. Rates of obstetric intervention among low-risk women giving birth in private and public hospitals in NSW: a population-based descriptive study. BMJ Open 2012;2:e001723. 18. Lau TK, Chung KH, Haines CJ, Chang AM. Fetal sex as a risk factor for fetal distress leading to abdominal delivery. Aust N Z J Obstet Gynaecol 1996;36:146–9. 19. Schuit E, Kwee A, Westerhuis ME, Van Dessel HJ, Graziosi GC, Van Lith JM, et al. A clinical prediction model to assess the risk of operative delivery. BJOG 2012;119:915–23.
Mode of Delivery Following Successful External Cephalic Version: Comparison With Spontaneous Cephalic Presentations at Delivery Simone M. I. Kuppens, MD, PhD,1 Eileen K. Hutton, RN, RM, PhD,2,3 Tom H. M. Hasaart, MD, PhD,1 Nassira Aichi, MD,1 Henrica A. Wijnen, PhD,4 Victor J. M. Pop, MD, PhD5 1
Department of Obstetrics and Gynaecology, Catharina Hospital, Eindhoven, the Netherlands
2
Department of Obstetrics and Gynaecology, McMaster University, Hamilton ON
3
Department of Midwifery Science VU Medical Center, Amsterdam, the Netherlands
4
Department of Midwifery Science, Zuyd University, Maastricht, the Netherlands
5
Department of Medical Health Psychology, University of Tilburg, Tilburg, the Netherlands
Abstract
Résumé
Objective: To compare the obstetric outcomes of pregnant women after successful external cephalic version (ECV) (cases) with a large group of pregnant women with a spontaneously occurring cephalic fetal position at delivery (controls).
Objectif : Comparer les issues obstétricales que connaissent des femmes enceintes à la suite de la réussite d’une version céphalique par manœuvres externes (VCE) (cas) à celles que connaissent un important groupe de femmes enceintes qui présentent un fœtus se trouvant spontanément en position céphalique au moment de l’accouchement (témoins).
Methods: We conducted a retrospective matched cohort study in a teaching hospital in the Netherlands. Delivery outcomes of women with a successful ECV were compared with those of women with spontaneously occurring cephalic presentations, controlling for maternal age, parity, gestational age at delivery, and onset of labour (spontaneous or induced). Exclusion criteria were a history of Caesarean section, delivery at < 35 weeks, and elective Caesarean section. The primary outcome was the prevalence of Caesarean section and instrumental delivery in both groups; secondary outcomes were the characteristics of cases requiring intervention such as Caesarean section or instrumental delivery. Results: Women who had a successful ECV had a significantly higher Caesarean section rate than the women in the control group (33/220 [15%] vs. 62/1030 [6.0 %]; P < 0.001). There was no difference in the incidence of instrumental delivery (20/220 [9.1%] vs. 103/1030 [10%]). Comparison of characteristics of women in the cases group showed that nulliparity, induction of labour, and occiput posterior presentation were associated with Caesarean section and instrumental deliveries. Conclusion: Compared with delivery of spontaneous cephalic presenta tions, delivery of cephalic presenting babies following successful ECV is associated with an increased rate of Caesarean section, especially in nulliparous women and women whose labour is induced. J Obstet Gynaecol Can 2013;35(10):883–888 Key Words: External cephalic version, breech presentation, Caesarean section, instrumental delivery Competing Interests: None declared. Received on December 1, 2012 Accepted on July 22, 2013
Méthodes : Nous avons mené une étude de cohorte appariée rétrospective au sein d’un hôpital universitaire des Pays-Bas. Nous avons comparé les issues de l’accouchement chez des femmes ayant subi une VCE réussie à celles de femmes ayant connu une présentation céphalique spontanée, tout en nous assurant de neutraliser les effets de l’âge maternel, de la parité, de l’âge gestationnel au moment de l’accouchement et de la nature de l’apparition du travail (spontané ou déclenchement). Parmi les critères d’exclusion, on trouvait les antécédents de césarienne, l’accouchement à < 35 semaines et la césarienne de convenance. Le critère d’évaluation principal était la prévalence de la césarienne et de l’accouchement instrumental dans les deux groupes; les critères d’évaluation secondaires étaient les caractéristiques des cas nécessitant une intervention (comme une césarienne ou un accouchement instrumental). Résultats : Les femmes ayant subi une VCE réussie ont présenté un taux de césarienne considérément plus élevé que celui des femmes du groupe « témoins » (33/220 [15 %] vs 62/1 030 [6,0 %]; P < 0,001). Aucune différence n’a été constatée en ce qui concerne l’incidence de l’accouchement instrumental (20/220 [9,1 %] vs 103/1 030 [10 %]). La comparaison des caractéristiques des femmes du groupe « cas » a révélé que la nulliparité, le déclenchement du travail et la présentation occipito-postérieure étaient associés aux accouchements par césarienne et instrumentaux. Conclusion : Par comparaison avec l’accouchement de fœtus en présentation céphalique spontanée, l’accouchement de fœtus adoptant une position céphalique à la suite d’une VCE réussie est associé à une hausse du taux de césarienne, particulièrement chez les nullipares et les femmes qui subissent un déclenchement du travail.
OCTOBER JOGC OCTOBRE 2013 l 883
Obstetrics
INTRODUCTION
P
erforming external cephalic version (ECV) is the best means of reducing the number of breech presentations and breech deliveries at term, and is recommended by the American Congress of Obstetricians and Gynecologists and the Royal College of Obstetricians and Gynaecologists.1–3 It is clear that ECV reduces the incidence of Caesarean section in women with a breech presentation.1 However, whether successful ECV affects the mode of delivery remains uncertain. Some studies have shown that Caesarean section and instrumental delivery rates are not increased after successful ECV,4–7 whereas other studies show the opposite.8–13 These different outcomes can be explained by differences between studies such as sample size, ethnic differences, and different proportions of nulliparous and multiparous patients (Table 1). Maternal age, parity, gestational age at delivery, and type of onset of labour (spontaneous or induced) are important determinants of mode of delivery that must be taken into account in such comparisons. Only one study, in 2009, matched study groups for all four of these variables and found that neither CS nor instrumental delivery rates were increased following successful ECV.7 However, a meta-analysis in 2004 showed a doubling of the incidence of intrapartum CS after successful version.14 These authors concluded that pregnancies after successful ECV should not be considered as normal pregnancies, and that these women should deliver in units where facilities for emergency CS and neonatal resuscitation are immediately available. With regard to our country (the Netherlands), this is an important issue because cephalic-presenting pregnancies after successful ECV are regarded as low-risk pregnancies and are referred back to primary midwifery care. We therefore performed a study comparing the obstetric outcomes of pregnant women who had a cephalic fetal position at delivery after successful ECV with a large group of pregnant women in which no ECV was performed and who presented with a spontaneously occurring cephalic fetal position at delivery. The primary outcome was the prevalence of CS and instrumental delivery in both groups. In a separate analysis we studied the characteristics of patients who had a CS or instrumental delivery after successful ECV. METHODS
We performed the study at the Catharina Hospital in Eindhoven, an academically affiliated, community-based hospital in the South East of the Netherlands. Data for the cases in this study were prospectively collected between 2007 and 2011 at the outpatient ECV clinic, where women were prospectively followed after an ECV attempt until 884 l OCTOBER JOGC OCTOBRE 2013
delivery. All women had a low-risk pregnancy without medical problems. After successful ECV, women were referred back to primary midwifery care. The ECV protocol used has been described in detail elsewhere.15 All the ECVs in our study were performed by the same two obstetricians working in unison. Only women who had a successful ECV and who presented with a cephalic position at delivery were included. The outcome of the ECV cohort was compared with a large control group of 1129 pregnant women drawn from the general population in the same area. Data from the control group were also prospectively collected as part of an observational study that was performed in low-risk women under primary midwifery care in the same area.16 From that study, women with a spontaneous cephalic position at delivery and in a gestational age range similar to the ECV group were used for comparison with the outcome of the ECV group. Exclusion criteria were patients with a previous history of CS, delivery < 35 weeks, and those who underwent a primary CS. This resulted in 220 women in the ECV group and 1030 women in the control group. The following obstetric parameters were defined. First, the start of labour was defined as spontaneous versus induced. In the latter, both patients with mechanical rupture of membranes and patients with medically induced labour were included. Second, the mode of delivery was defined as spontaneous vaginal delivery, instrumental delivery, and secondary CS. Possible differences between the cases and control subjects with regard to these parameters were compared. Nonprogressive labour was defined as lack of cervical dilatation over two to four hours despite adequate uterine contractions. Statistical analysis was performed using SPSS Version 19.0 (IBM Corp., Armonk NY). We performed t tests (two-tailed) and chi-square tests (and Fisher exact tests when appropriate) to compare obstetric characteristics and birth outcomes between the two groups. Finally, within the ECV group we compared the characteristics of those who had a spontaneous vaginal delivery versus those who needed intervention such as CS or instrumental delivery. The study was approved by the Medical Ethics Committee of the Catharina Hospital in Eindhoven, the Netherlands. RESULTS
From January 2007 to January 2011, ECV was performed on 438 women, of whom 280 (64%) were nulliparous. In 259/438 women (59%) ECV was successful. The mean gestational age at version was 36+1 weeks (SD 1 day) with a range of 35+4 weeks to 41+0 weeks. The mean interval from version to delivery was 4+0 weeks (SD 1.5 weeks) with a range of one day to 7+3 weeks.
Mode of Delivery Following Successful External Cephalic Version: Comparison With Spontaneous Cephalic Presentations at Delivery
Table 1. Reports of Caesarean section after successful ECV Authors Year of publication
Matching criteria
Sample size
Findings
Egge et al. 19944
Parity Gestational age at delivery Date of delivery
Cases 76 Control subjects 76
No significant difference in the CS rate between cases and control subjects (8% vs. 6%)
Laros et al. 19958
No matching
Cases 174
CS rate is higher in ECV group (31% vs. 15%) Reasons: failed induction and failed progress of labour
Lau et al. 19979
Age Parity Onset of labour
Cases 154 Control subjects 308
CS rate is higher in ECV group (16.9% vs. 7.5%, P < 0.005)
Siddiqui et al. 19995
No matching
Cases 92 Control subjects 184
No significant difference in the CS rate between study patients and control patients (22.8% vs. 23.4%)
Wax et al. 20006
Gestational age at delivery Labour onset Prior vaginal delivery Cervical dilatation on admission
Cases 38 Control subjects 114
No significant difference in the CS rate between cases and control subjects (3/38 vs. 1/114). No significant instrumental delivery rate (4/38 vs. 8/114) No increase in oxytocin use or labour duration
Chan et al. 200210
No matching
Cases 279 Control subjects 28447
CS rate is higher in ECV group (23.3% vs. 9.4%, aOR 3.6, CI 2.4 to 5.3) Instrumental delivery is higher in ECV group (14.3% vs. 12.8%, aOR 1.7, CI 1.1 to 2.4) Labour by induction is higher in ECV group (24% vs. 13.4%, OR 2.0, CI 1.5 to 2.7) Reasons: more fetal distress, more failure to progress, more failed induction More cases requiring epidural anaesthesia and surgical augmentation
Ben-Haroush et al. 200211
Age Gravidity Parity Ethnicity
Cases 96 Control subjects 192
CS rate is higher in ECV group (19.8% vs. 6.25%) Reasons: more failure to progress and malpresentation No difference in instrumental deliveries
Vézina et al. 200412
Parity
Cases 301 Control subjects 301
More CS in cases: 25.1% vs. 10.5% (P < 0.001) Nulliparous OR 2.04; 95% CI 1.13 to 3.68 Multiparous OR 4.30 95% CI 1.76 to 10.54 Reasons: more labour dystocia In multiparous more instrumental deliveries in cases (8.7% vs. 2.7%, P = 0.02). In multiparous also more suspected fetal distress
Clock et al. 20097
Parity Prior CS Gestatational age at delivery Labour onset
Cases 197 Control subjects 394
CS was not significant between the groups (16.8% vs. 11.9%)
Jain et al. 201013
No matching
Cases 93 Control subjects 103
More CS in cases: 18.2% vs. 7.7% (P < 0.028) No difference in rate of instrumental deliveries.
Because we performed primary CS in four cases and had missing data on delivery in 35 women, we excluded them from the study. The remaining 220 women were compared with 1030 women from a control group of 1129 who presented with a spontaneous cephalic position at delivery. The characteristics of the 220 cases and 1030 control subjects are shown in Table 2. The baseline characteristics were similar between the study and the control populations with respect to maternal age, gestational age at delivery, birth weight, and sex of the newborn, as well as the number of neonates with low
Apgar scores after five minutes. There were significantly more primiparous women in the ECV group. Labour characteristics and differences between the version and the control group are shown in Table 3. The CS rate was significantly (2.5 times) higher for women who presented with cephalic position after successful ECV than for control subjects (33/220 [15%] vs. 62/1030 [6%]; P < 0.001). There was no difference in the incidence of instrumental delivery between version and control group. Indications for CS such as dystocia in the first stage of labour, dystocia in the second stage of labour, or fetal distress were similar for the study and the control groups. OCTOBER JOGC OCTOBRE 2013 l 885
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Table 2. Characteristics of the study population Cases n = 220
Control subjects n = 1030
P
31.2 (3.9)
30.5 (3.6)
0.89*
21 to 40
22 to 41
0
121 (55)
484 (47)
≥1
99 (45)
546 (53)
40.1 (1)
40 (1.3)
35.4 to 43
35.4 to 42.9
Maternal age, years Mean (SD) Range Parity, n (%) 0.031†
Gestational age at delivery, weeks Mean (SD) Range
0.18*
Birth weight, grams Mean (SD)
3443 (465)
3519 (489)
1765 to 4650
1975 to 4972
Male
110 (50)
554 (54)
Female
110 (50)
476 (46)
2 (0.9)
11 (1.1)
Range
0.09*
Sex of the neonate, n (%)
Apgar 5 min < 7, n (%)
0.31† 0.83†
*t test †χ2 test
Table 3. Labour and delivery outcome of the study population ECV n = 220 n (%)
Control subjects n = 1030 n (%)
Onset of labour
0.58
Spontaneous
183 (83)
872 (85)
Induction
37 (17)
158 (15)
167 (76)
865 (84)
Operative vaginal
20 (9)
103 (10)
Caesarean section
33 (15)
62 (6)
Delivery outcome Spontaneous vaginal
Reasons for operative vaginal delivery
< 0.001
n = 20
n = 103
Fetal distress
9 (45)
41 (40)
Dystocia in second stage
11 (55)
62 (60)
Reasons for Caesarean section
n = 33
n = 62
Fetal distress
14 (42)
21 (34)
Dystocia in first stage
10 (30)
27 (44)
Dystocia in second stage
9 (28)
14 (22)
Occiput anterior
205 (93)
952 (92)
Occiput posterior
15 (7)
78 (8)
Cephalic presentation
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P (χ2 test)
0.41
0.45
0.70
Mode of Delivery Following Successful External Cephalic Version: Comparison With Spontaneous Cephalic Presentations at Delivery
Table 4. Comparison of characteristics of vaginal deliveries and instrumental deliveries or Caesarean sections within the group of women with a successful ECV (N = 220) Vaginal deliveries n = 167
Caesarean sections and instrumental deliveries n = 53
Maternal age, years Mean (SD)
31 (4.4)
30.4 (6.0)
Range
22 to 40
20 to 39
0
74 (44.3)
47 (88.7)
≥1
93 (55.7)
6 (11.3)
Parity, n (%)
< 0.001†
Time interval from ECV to delivery, weeks
0.38*
Mean (SD)
4.0 (1.4)
4.2 (1.6)
Range
0 to 7.3
0 to 6.7
39+6 (3.3)
40+3 (1.3)
35+5 to 43+0
35+1 to 42+4
3398 (520)
3525 (507)
2120 to 4650
1950 to 4515
Gestational age at delivery, weeks+days Mean (SD) Range
0.33*
Birth weight Mean (SD) Range
P 0.41*
0.12*
Sex of the neonate, n (%)
0.15†
Male
79 (47)
31 (58)
Female
88 (53)
22 (42)
0 ( 0)
2 (4)
Apgar 5 min < 7, n (%) Onset of labour, n (%)
0.06† 0.003†
Spontaneous
146 (87.4)
37 (69.8)
Induction
21 (12.6)
16 (30.2)
Occiput anterior
164 (98)
41 (77)
Occiput posterior
3 (2)
12 (23)
Presentation of head position, n (%)
< 0.001†
*t test †χ2 test
When stratified for parity, the CS rate for nulliparous women in the version group was 29/121 (24%) compared with 48/484 (10%) in the control group (P < 0.001). In multiparous women, the CS rate in the version group was not statistically different from the control group (4/99 [4%] vs. 17/546 [3.2%]; P = 0.64). When stratified for induced onset of labour, the CS rate in the version group was 14/37 (38%) compared with 8/158 (5%) in the control group (P < 0.001). Comparison of characteristics of women in the version group showed that nulliparity, induction of labour, and occiput posterior presentation were associated with Caesarean section and instrumental delivery (Table 4). DISCUSSION
We found that ECV resulting in a cephalic position at delivery is associated with a higher risk of CS than in women
with a spontaneous cephalic position at delivery, while the incidence of instrumental delivery is not increased. This is in agreement with several other studies.8–13 However, four previous studies showed no increased risk of CS after successful ECV.4–7 Three of those studies had low sample size.4–6 However, the fourth study, published in 2009, did have an appropriate sample size (197 cases) and matched women undergoing ECV with a control group with respect to parity, gestational age at delivery, onset of labour, and maternal age.7 The difference between that study (by Clock et al.) and ours is that the study population of Clock et al. consisted of only 38% nulliparous patients, compared with 55% in our study. Furthermore, the CS rate in the study of Clock et al. was lower than expected and therefore a type 2 error could not be excluded. In our study, a post hoc analysis showed that the power of our study was 89% when accepting a type 1 error of 0.05. OCTOBER JOGC OCTOBRE 2013 l 887
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Nulliparity, induction of labour, and occiput posterior presentation are risk factors for CS after successful ECV. These factors have also been reported for the general popu lation, but are especially true for labour after ECV.10,12,17–19
REFERENCES 1. Hofmeyr GJ, Kulier R. External cephalic version for breech presentation at term. Cochrane Database Syst Rev 2012;10:CD000083.
The higher reported incidence of intrapartum CS following successful ECV has been attributed to labour dystocia and fetal distress.10–14 In our study, labour dystocia accounted for 19/33 (58%) of deliveries by CS and fetal distress for 14/33 (42%). The explanation could be that the underlying pathophysiology of breech presentation is partly similar to that of obstructive labour. Furthermore, fetuses in a breech position are more susceptible to the burden of the physical stress of labour than their cephalic counterparts.10,14
2. American College of Obstetricians and Gynaecologists (ACOG). External cephalic version. ACOG Practice Bull 2000; Number 13.
Several authors have recommended that labour after successful ECV warrants careful monitoring and should be considered to be high risk,9,10,14 in which case these patients will be need to be referred to an obstetrician for care. However, from Table 3 it can be seen that there is still a good chance of spontaneous vaginal birth after successful ECV. Therefore we conclude that women may keep their choice of place of delivery and care provider after successful ECV. However, they should be informed, and should take into consideration, that there is an increased risk of abnormal labour resulting in CS in nulliparous women and women whose labour is induced after ECV.
6. Wax JR, Sutula K, Lerer T, Steinfeld JD, Ingardia CJ. Labor and delivery following successful external cephalic version. Am J Perinatol 2000;17:183–6.
A limitation of our study is that we did not include BMI, oxytocin use, rates of epidural analgesia, and fetal surveillance in labour in our analysis. Furthermore, there were more nulliparous women in the ECV group than in the control group. The strength of our study is that the data were all collected prospectively and constitute the third largest sample to be published to date (after Vezina et al.12 and Chan et al.10). It contains a high proportion of nulliparous women (55%), who have the highest incidence of breech presentation towards term of all parity groups. We were able to compare our ECV group with a large sample of pregnant women from the same area. Finally, all the ECVs in our study were performed by the same two obstetricians, resulting in a low potential for inter-assessor variability. CONCLUSION
Although overall CS rates were below 15%, we found that delivery after successful ECV is associated with a 2.5 times higher rate of CS in comparison with spontaneous cephalic presentations. Women, particularly those who are nulliparous and whose labour is induced, should be informed about this increased risk, and care providers should take this into consideration when recommending where these women should give birth.
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3. Royal College of Obstetricians and Gynecologists (RCOG). The national sentinel caesarean section audit report. London: RCOG Press; 2001. 4. Egge T, Schauberger C, Schaper A. Dysfunctional labor after external cephalic version. Obstet Gynecol 1994;83:771–3. 5. Siddiqui D, Stiller RJ, Collins J, Laifer SA. Pregnancy outcome after successful external cephalic version. Am J Obstet Gynecol 1999;181:1092–5.
7. Clock C, Kurtzman J, White J, Chung JH. Cesarean risk after successful external cephalic version: a matched, retrospective analysis. J Perinatol 2009;29:96–100. 8. Laros RK Jr, Flanagan TA, Kilpatrick SJ. Management of term breech presentation: a protocol of external cephalic version and selective trial of labor. Am J Obstet Gynecol 1995;172:1916–25. 9. Lau TK, Lo KW, Rogers M. Pregnancy outcome after successful external cephalic version for breech presentation at term. Am J Obstet Gynecol 1997;176:218–23. 10. Chan LY, Leung TY, Fok WY, Chan LW, Lau TK. High incidence of obstetric interventions after successful external cephalic version. BJOG 2002;109:627–31. 11. Ben-Haroush A, Perri T, Bar J, Yogev Y, Bar-Hava I, Hod M, et al. Mode of delivery following successful external cephalic version. Am J Perinatol 2002;19:355–60. 12. Vézina Y, Bujold E, Varin J, Marquette GP, Boucher M. Cesarean delivery after successful external cephalic version of breech presentation at term: a comparative study. Am J Obstet Gynecol 2004;190:763–8. 13. Jain S, Mulligama C, Tagwira V, Guyer C, Cheong Y. Labour outcome of women with successful external cephalic version: a prospective study. J Obstet Gynaecol 2010;30:13–6. 14. Chan LY, Tang JL, Tsoi KF, Fok WY, Chan LW, Lau TK. Intrapartum cesarean delivery after successful external cephalic version: a metaanalysis. Obstet Gynecol 2004;104:155–60. 15. Kuppens SM, Waerenburgh ER, Kooistra L, van der Donk RW, Hasaart TH, Pop VJ. The relation between umbilical cord characteristics and the outcome of external cephalic version. Early Hum Dev 2011;87:369–72. 16. Rayman MP, Wijnen H, Vader H, Kooistra L, Pop V. Maternal selenium status during early gestation and risk for preterm birth. CMAJ 2011;183:549–55. 17. Dahlen HG, Tracy S, Tracy M, Bisits A, Brown C, Thornton C. Rates of obstetric intervention among low-risk women giving birth in private and public hospitals in NSW: a population-based descriptive study. BMJ Open 2012;2:e001723. 18. Lau TK, Chung KH, Haines CJ, Chang AM. Fetal sex as a risk factor for fetal distress leading to abdominal delivery. Aust N Z J Obstet Gynaecol 1996;36:146–9. 19. Schuit E, Kwee A, Westerhuis ME, Van Dessel HJ, Graziosi GC, Van Lith JM, et al. A clinical prediction model to assess the risk of operative delivery. BJOG 2012;119:915–23.
