BJOG: an International Journal of Obstetrics and Gynaecology DOI: 10.1111/j.1471-0528.2004.00518.x May 2005, Vol. 112, pp. 627–631 Tocolysis for repeat external cephalic version in breech presentation at term: a randomised, double-blinded, placebo-controlled trial Lawrence Impey,a Meghana Panditb Background External cephalic version (ECV) reduces the incidence of breech presentation at term and caesarean section for non-cephalic births. Tocolytics may improve success rates, but are time consuming, may cause side effects and have not been proven to alter caesarean section rates. The aim of this trial was to determine whether tocolysis should be used if ECV is being re-attempted after a failed attempt. Objective To determine whether tocolysis should be used if ECV is being re-attempted after a failed attempt. Design Randomised, double-blinded, placebo-controlled trial. Setting UK teaching hospital. Population One hundred and twenty-four women with a breech presentation at term who had undergone an unsuccessful attempt at ECV. Methods Relative risks with 95% confidence intervals for categorical variables and a t test for continuous variables. Analysis was by intention to treat. Main outcome measures Incidence of cephalic presentation at delivery. Secondary outcomes were caesarean section and measures of neonatal and maternal morbidity. Results The use of tocolysis for a repeat attempt at ECV significantly increases the incidence of cephalic presentation at delivery (RR 3.21; 95% CI 1.23–8.39) and reduces the incidence of caesarean section (RR 0.33; 95% CI 0.14–0.80). The effects were most marked in multiparous women (RR for cephalic presentation at delivery 9.38; 95% CI 1.64–53.62). Maternal and neonatal morbidity remain unchanged. Conclusions The use of tocolysis increases the success rate of repeat ECV and reduces the incidence of caesarean section. A policy of only using tocolysis where an initial attempt has failed leads to a relatively high success rate with minimum usage of tocolysis. INTRODUCTION whether it is best administered before every attempt at ECV or whether it should be used only after a failed attempt. Breech presentation occurs at birth in 3–4% of all The aim of this trial was to test the null hypothesis that deliveries and is a major contributor to the caesarean tocolysis for a repeat ECV (i.e. after a failed ECV) does not section rate.1 This problem has increased2 following the increase the success rates of ECV. publication of the Term Breech Trial.3 Although external cephalic version (ECV) reduces both the incidence of breech presentation at delivery and the caesarean section METHODS rate,4 this effect is limited by low success rates, especially in white British women.5 Tocolysis may improve success, The trial was undertaken in the breech clinic, held in but the effect on non-cephalic births is limited.6 It is also the delivery ward of the John Radcliffe Hospital, Oxford. time consuming and may be unpleasant, and it is not known Ethical approval for the study was obtained from the Cen- tral Oxford Research Ethics Committee (C00.024) in April 2000. Women were referred to the clinic from hospital or community clinics, including those attached to other a local hospitals, if they had a singleton breech presenta- Obstetrics and Fetal Medicine, Oxford Fetal Medicine tion at 36 or more (nulliparous) or 37 or more (multiparous) Unit, Level 6, The Women’s Centre, John Radcliffe weeks. Health professionals were encouraged to refer all Hospital, Oxford, UK b breech presentations to the clinic for ECV before consid- Obstetrics and Gynaecology, Milton Keynes General ering contraindications or counselling regarding mode of Hospital, UK delivery. Correspondence: Mr L. Impey, Oxford Fetal Medicine Unit, Level 6, Women were eligible for the trial if they had undergone The Women’s Centre, John Radcliffe Hospital, Oxford, OX3 9DU, UK. an unsuccessful attempt at ECV (without tocolysis) for a D RCOG 2004 BJOG: an International Journal of Obstetrics and Gynaecology www.blackwellpublishing.com/bjog 628 L. IMPEY & M. PANDIT allocations in sealed numbered opaque envelopes opened in sequential order on the delivery ward. Both the patient and the ECV operator were blinded to the result of random- isation, including maternal observations, and the latter was not allowed to enquire about side effects. Tocolysis was administered as ritodrine hydrochloride (Yutopar) infusion of 50 mg (10 mg/mL) added to 12 mL dextrose saline (total 17 mL of ritodrine 3 mg/mL). This was administered by a syringe pump, starting at 1 mL/hour and increasing at 10-minute intervals to a maximum of 5 mL/hour, provided the maternal pulse did not exceed 120/minute. The placebo consisted of 17 mL dextrose sa- line solution by the same route and in similar increments, for a maximum of 50 minutes. Maternal pulse and blood pressure were measured every 10 minutes in both arms. ECV was re-attempted at 50 minutes or when the maternal pulse exceeded 120/minute, whichever was sooner. Wher- ever possible, the repeat ECV was performed by the same operator as for the first attempt. Data were collected prospectively by the research mid- wife. The primary outcome was the incidence of cephalic presentation at delivery. For the power calculation, we estimated a spontaneous version rate in the control group of 5%.7 Tocolysis for all women increases success rates from approximately 40% to 55%.8,9 Therefore, of the 60 women out of 100 who have had a failed attempt with- out tocolysis, a further 15 (25%) could reasonably be ex- pected to have a second successful attempt with tocolysis. To detect an increase in the incidence of cephalic presen- tation from 5% to 25% with 90% power (a ¼ 0.05), 124 patients were required. Secondary outcomes were the incidence of successful ECV, incidence of caesarean section, length of hospital inpatient stay, incidence of neonatal Apgar scores <7at Fig. 1. Trial profile. 5 minutes, neonatal intensive care unit admission or other rarer neonatal outcomes and mean cord arterial pH. A patient assessment of discomfort using an abbre- viated, modified McGill pain intensity score10 was also breech presentation. They were required to have had a compared. normal cardiotocograph following this, and no potential Analysis was by intention to treat. For categorical contraindications to the use of ritodrine (cardiac disease, variables, relative risks were calculated, with 95% confi- pre-existing or gestational diabetes, hypertension). Women dence intervals. Continuous variables, where normally ineligible for an initial attempt at ECV were those with a distributed, were compared by a t test. pre-existing indication for caesarean section, suspected unstable lie, pre-eclampsia, recent (<4 weeks) antepartum haemorrhage, suspected fetal compromise (abdominal cir- Table 1. Demographics. Values are presented as n (%) or mean [SD]. cumference below the third centile, with either an umbilical Tocolysis (n ¼ 62) Placebo (n ¼ 62) artery resistance index above the 97th centile or deepest amniotic fluid pocket <2 cm) or rhesus isoimmunisation. Maternal age 30.6 [4.5] 30.9 [5.5] Information sheets regarding the trial were given in ad- Nulliparous 44 (71.0) 45 (72.6) Booking weight 66.5 [13.1] 63.0 [12.0] vance of the initial ECV attempt. After a failed attempt on Height (cm) 164.6 [7.8] 165.3 [5.7] an eligible patient, written consent was obtained by the re- Caucasian race 61 (98.4) 61 (98.4) search midwife. Consenting patients were then randomly Extended breech 38 (61.3) 42 (67.7) allocated, in a ratio of 1:1, to receive either tocolysis or Liquor pool depth (mm) 43.3 [16.0] 47.7 [13.7] placebo for a repeat attempt at ECV. Randomisation was Duration first ECV (minutes) 9.1 [2.1] 9.5 [2.7] Gestation at ECV (weeks) 37.5 [0.81] 37.5 [0.85] achieved using random block sizes up to 20, with the D RCOG 2004 BJOG: an International Journal of Obstetrics and Gynaecology 112, pp. 627–631 RANDOMISED TRIAL OF TOCOLYSIS FOR A REPEAT EXTERNAL CEPHALIC VERSION 629 Table 2. Effect of tocolysis. The values are presented as n (%) or mean [SD]. Tocolysis (n ¼ 62) Placebo (n ¼ 62) RR (95% CI)/P Primary outcome Cephalic presentation at delivery 19 (29.0) 7 (11.3) 3.21 (1.23–8.39) Secondary outcomes Successful ECV 17 (27.4) 5 (8.1) 4.31 (1.48–12.57) Caesarean section 41 (66.1) 53 (85.5) 0.33 (0.14–0.80) Elective caesarean 40 (64.5) 48 (77.4) 0.53 (0.24–1.17) Breech delivery 5 (6.5) 5 (6.5) 1.00 (0.24–4.19) Birthweight (g) 3169 [484] 3310 [429] P ¼ 0.658 Gestation at delivery (weeks) 40.0 [1.2] 38.8 [1.0] P ¼ 0.076 SCBU admission 2 (3.2) 2 (3.2) 1.00 (0.14–7.33) Length SCBU stay (days) 0.11 [0.76] 0.08 [0.45] P ¼ 0.831 Apgar < 7at5 0 0 Mean arterial pH 7.25 [0.07] 7.26 [0.08] P ¼ 0.752 Neonatal seizures 0 0 McGill score 2.3 [0.7] 2.1 [0.7] P ¼ 0.303 Maternal stay (days) 3.9 [0.3] 4.4 [0.3] P ¼ 0.176 Maternal morbidity 0 0 Data were entered prospectively on a database SPSS 8.0 An increase in cephalic presentation at delivery was (Chicago, Illinois). Demographic and antenatal data were found (Table 2). This was due to an increase in the success obtained retrospectively at the time of recruitment. Out- of repeat ECV and was followed by a decrease in the inci- come details were collected retrospectively from hospital dence of caesarean section.