Tocolysis in term breech external cephalic version - Rima

International Journal of Gynecology and Obstetrics (2005) 88, 5—8
www.elsevier.com/locate/ijgo
CLINICAL ARTICLE
Tocolysis in term breech external cephalic version
M.I. Nor Azlin*, H. Haliza, Z.A. Mahdy, I. Anson, M.N. Fahya, M.A. Jamil
Department of Obstetric and Gynaecology, Hospital Universiti Kebangsaan Malaysia,
Jalan Yaacob Latiff, 56000 Kuala Lumpur, Malaysia
Received 5 April 2004; received in revised form 31 August 2004; accepted 7 September 2004
KEYWORDS
External cephalic
version;
Breech presentation;
Ritodrine;
Tocolysis
Abstract
Objectives: To study the effect of ritodrine tocolysis on the success of external
cephalic version (ECV) and to assess the role of ECV in breech presentation at
our centre. Material and methods: A prospective randomized double-blindcontrolled
trial comparing ritodrine and placebo in ECV of singleton term breech
pregnancy at a tertiary hospital. Results: Among the 60 patients who were
recruited, there was a success rate of 36.7%. Ritodrine tocolysis significantly
improved the success rate of ECV (50% vs. 23%; P=0.032). There was a marked
effect of ritodrine tocolysis on the ECV success in nulliparae (36.4% vs. 13.0%)
and multiparae (87.5% vs. 57.1%). External cephalic version has shown to reduce
the rate of cesarean section for breech presentation by 33.5% in our unit.
Conclusion: External cephalic version significantly reduced the rate of cesarean
section in breech presentation, and ritodrine tocolysis improved the success of
ECV and should be offered to both nulliparous and parous women in the case of
term breech presentation.
D 2004 International Federation of Gynecology and Obstetrics. Published by
Elsevier Ireland Ltd. All rights reserved.
1. Introduction
The management of breech presentation at term
has always been emotive and controversial. Since a
report on a randomized multicentre trial by Hannah
et al. [1] who advocated that a planned cesarean
section in breech presentation at term is safer for
* Corresponding author. Tel.: +60 3 91703043; fax: +60 3
91738946.
E-mail address: azlinm@mail.hukm.ukm.my (M.I. Nor Azlin).
neonates than vaginal birth, external cephalic
version (ECV) has been recommended [2,3] as an
alternative to cesarean section.
External cephalic version is safe and substantially
reduces the need for cesarean delivery in
breech presentation [4]. Nevertheless, it is not
always successful, and strategies including tocolysis
[5] have been implemented to improve success.
Although earlier studies [6,7] compared ritodrine
HCl (Yutopar; Solvay Pharmaceutical, Weesp,
Holland) and placebo, the present study was
0020-7292/$ - see front matter D 2004 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd.
All rights reserved.
doi:10.1016/j.ijgo.2004.09.014

6
undertaken in our centre to ascertain the effect of
tocolysis with ritodrine on the success of ECV. It was
also to assess the role of ECV for breech presentation
at term by practitioners who were developing
this new skill at our centre.
2. Materials and methods
This prospective double-blinded randomized controlled
trial was performed in a tertiary (teaching)
hospital with 5000 deliveries annually. The procedure
was offered to all women seen at the
antenatal clinic with a singleton fetus in breech
presentation at 37 weeks of pregnancy and beyond.
The exclusion criteria were:
(1) a previous cesarean section or other uterine
scar (such as a myomectomy scar), or uterine
malformation;
(2) the present pregnancy complicated by antepartum
hemorrhage, hypertension, diabetes
mellitus, intrauterine growth restriction
(fetus b10th percentile for gestational age)
or oligohydramnios (amniotic fluid index of 5
and below);
(3) pregnancy with fetal anomalies;
(4) early or active phase of labor;
(5) contraindications to intravenous ritodrine
infusion or to vaginal delivery even if the
fetus were in vertex presentation.
The patients fasted overnight and were admitted
as day cases. A 20-min nonstress cardiotocography
(CTG) was performed to verify fetal wellbeing,
followed by an ultrasound scan to confirm
the presentation, fetal size, placental location,
and amniotic fluid index. If any of these were
abnormal, the patient was excluded from the
study. Written informed consent was obtained in
all cases, and the study was conducted in the
clinical trials ward.
The patients were randomized to the treatment
or placebo group in a sequence generated by a
computerized random number generator, and their
assignment was sealed in numbered opaque envelopes.
The active treatment (0.4 mg/mL of ritodrine
in 5% dextrose) and placebo were supplied in
identical form as an intravenous infusion and
administered via a syringe pump at the rate of
1.5 mL/min, beginning 15 min before and continuing
throughout the procedure.
The obstetricians attempting the ECV were
blinded to the group assignment of their patients
throughout the procedure. Blood pressure measurements
and pulse rates of patients were recorded
continuously. The ECV was done within 5 min with a
maximum of 3 attempts. The forward-roll or back
flip techniques was used. The procedure was
abandoned if undue force was required or patient
became distressed. At the end of the procedure, an
ultrasound scan to confirm presentation and a 20-
min CTG assessing fetal well-being were repeated.
If no complications arose, the patients were
allowed to return home and be managed by the
team responsible for antenatal care.
The study was focused on determining whether
ritodrine tocolysis improves the success rate of
ECV compared with placebo for practitioners
learning the skill. Outcome data were the success
rate of the procedure (i.e., cephalic presentation
following ECV) and possible complications. Demographic
data on maternal and fetal characteristics,
mode of delivery, and presentation at labor were
also taken into consideration. A total of 60
patients (30 patients on each arm) were recruited
based on an a error of 0.05 and a h of 0.2.
Statistical analyses were performed using the t
test or the controlled Cochran—Mantel—Haenszel
test. A P value less than 0.05 was considered
statistically significant. The study was reviewed
and approved by our institutional ethical and
research committee.
3. Results
M.I. Nor Azlin et al.
Patient characteristics were similar in both groups,
as shown in Table 1. Half (50%) of the ECVs was
performed at 37 weeks of pregnancy; however,
most of the successful ones were done at 38 weeks
(Table 1). Birth weights in the ritodrine and placebo
groups were similar (3.05F0.31 vs. 3.14F0.42 kg,
respectively).
The overall success rate was 36.7%. Table 2
shows that the success rate of ECV was significantly
higher in the ritodrine group than in the
placebo group even after controlling for parity
(50% vs. 23.3%; P=0.03). In the ritodrine group, 8
of 22 nulliparous patients (36.4%) had a successful
ECV compared with 13% nulliparous (3 of 23
patients) in the placebo group. There was also
improvement in the success rate of ECV done with
tocolysis in parous women (87.5% vs. 57.1%;
P=0.058) (Table 2).
At delivery, those women with successful ECVs
had cephalic presentations while in labor, except
for one woman in whom the fetus had reversed to
breech presentation and another with fetal distress.
Both (9.1% of successful ECVs) had a cesarean

Tocolysis in term breech external cephalic version 7
Table 1
Characteristics of the study and control groups
Ritodrine group (n=30)
Placebo group (n=30)
Maternal age (years) 29.13F4.49 27.5F4.28
Amniotic fluid index, meanFS.D. 15.2F4.18 14.6F3.67
Nulliparous (%) 22 (73.3) 23 (76.6)
Frank breech (%) 18 (60) 14 (46.6)
Gestational age at ECV (week) Success Failure Success Failure
37 5/12 (41.7%) 7/12 (58.3%) 5/18 (27.7%) 13/18 (72.3%)
38 8/12 (66.7%) 4/12 (33.3%) 1/6 (16.7%) 5/6 (83.3%)
39 and more 2/6 (33.3%) 4/6 (66.7%) 1/6 (16.7%) 5/6 (83.3%)
section. All women with failed ECVs had cesarean
sections, and none of the fetuses had a spontaneous
cephalic version. All newborns who underwent a
successful ECV had an Apgar scores higher than 8 at
5 min. Two newborns in the group of unsuccessful
ECVs had an Apgar score of less than 5 at 5 min and
were admitted to the neonatal unit with the
diagnosis of congenital pneumonia. However, they
were well and discharged 2 days later.
4. Discussion
External cephalic version is known to be a safe
procedure causing minimal fetal and maternal
complications, as seen in this study. Although
ECV is highly recommended for breech presentation,
many women with a fetus in breech
presentation were not made aware of the option
[8]. For example, only 43% of consultant obstetricians
in England perform ECVs, although various
training methods have been adopted to
improve their skills and the success rate of ECV
Table 2 Maternal and fetal data in ritodrine vs.
placebo group
Ritodrine Placebo
Cephalic presentation
15/30 (50.0) 7/30 (23.7)
following ECV (%)
Parity=0 8/22 (36.4) 3/23 (13.0)
ParityN0 7/8 (87.5) 4/7 (57.1)
Presentation at delivery
following successful ECV (%)
Cephalic 14/15 (93.3) 7/7 (100)
Breech 1/15 (6.7) 0/7 (0)
Mode of delivery following
successful ECV (%)
Vaginal birth 13/15 (86.7) 7/7 (100)
Cesarean section 2/15 (13.3) 0/7 (0)
Apgar score (b5 at 1 min) 1 1
Admission to NICU, (no. of babies) 1 1
Birth weight (kg) 3.05F0.31 3.14F0.42
[9]; very few obstetricians perform the procedure
at our hospital.
Tocolysis has been used as one of the strategies
to increase the success of ECV, its major benefit
being a reduction in the amount of force required
to turn the fetus [10], particularly for obstetricians
who are learning the procedure [11,6]. In our study,
the overall success rate was slightly lower (36.7%),
most likely because of the learning process. Ritodrine
tocolysis in this study has significantly
improved the success rate of ECV not only in
nulliparous women but, interestingly, also in multiparous
women among whom the success rate is
already always higher. This finding suggests that
tocolysis should be offered to both nulliparous and
parous women.
The rate of cesarean section in the successful
ECV group was low in this study, although it has
varied in previous studies [4,12]. External cephalic
version was able to reduce the rate of
cesarean section for breech presentation by
33.5% in our unit, thus reducing the burden of
health care costs. Unfortunately, the women in
whom ECV did not succeed had a cesarean
section, which reflects current practice in our
unit and the preference of women with a fetus in
breech presentation.
Strict selection criteria were chosen in this study
to ensure the safety of the procedure, especially in
a centre with limited prior experience in performing
ECV. Adherence to the study protocol, with no
hesitation to abandon the procedure to avoid
complications, could explain the lower success rate
in this study.
In conclusion, our results showed that ritodrine
tocolysis improved the success rate of ECV in
term breech presentation and should be offered
to both nulliparous and parous women undergoing
ECV. ECV in term breech presentation has significantly
reduced the rate of cesarean sections in
our unit where vaginal breech delivery has not
been a common practice since the term breech
trial [1].

8
Acknowledgment
We thank the Universiti Kebangsaan Malaysia for its
financial support.
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