Thursday, November 01, 2012

Safely increase vaginal breech rates with a written protocol

A 2011 study at a tertiary hospital in France found that implementing a written consensus protocol for breech increased the rates of vaginal breech birth without compromising safety. From 2000-2004, before the protocol was implemented, the vaginal breech birth rate was 24% (planned rate 30%). Once the protocol was adopted in 2004, vaginal breech rates began rising. The rate averaged 38.5% (planned rate 44.5%). The study included 1133 breech presentations at term over the 8-year period. After the study ended in 2008, the vaginal breech rate continued to rise, exceeding 50% in 2009.

Here are more specifics on the written protocol:
Before 2003, the authors’ department had no written protocol for breech delivery, except for the general French recommendations for radiographic assessment of maternal pelvimetry and ultrasonographic evaluation of fetal size. The authors’ team set up a working group to develop a protocol to decide the type of delivery for breech presentations as an institutional change of practice. The staff approved the final protocol by consensus in June 2004. It was based on practices followed locally by obstetricians, but not previously described or discussed in writing. The protocol indicated that external cephalic version should be proposed before 36 weeks of gestation, and X-ray pelvimetry should be offered around 36–37 weeks of gestation to women whose fetus remained in breech presentation. A fetal ultrasound was also planned to measure biparietal diameter, estimate fetal weight, and verify that the head was not hyperextended (a contraindication to attempted vaginal delivery in the protocol). This ultrasound was to take place in the delivery room unless a previous ultrasound had been taken within the last 7 days. The biparietal diameter was compared with the results of the pelvic measurements. Regardless of whether the breech presentation was frank or complete, vaginal delivery was considered appropriate when three conditions were met: (1) obstetric conjugate– biparietal diameter 15 mm; (2) median transverse diameter– biparietal diameter 25 mm; and (3) interspinous diameter– biparietal diameter 0 mm. In all other situations, vaginal delivery was considered inappropriate. A further condition for vaginal delivery was an estimated fetal weight 3800 g in nulliparous women (there was no cut-off for parous women). A woman arriving in labour without any previous pelvimetry could only have a vaginal delivery if the fetal weight, estimated by ultrasound, was <2500 g or if she had previously had a vaginal delivery of an infant weighing >3800 g. A previous caesarean section and uterine malformations were not contra-indications to vaginal delivery. All women had continuous electronic fetal monitoring during labour. All breech deliveries were performed with an anaesthetist and an obstetrician experienced in the necessary manoeuvres present in the delivery room. In all cases, this information was given to the woman and discussed with her when the measurements were compared.

The authors discussed their findings in relation to the Hannah Term Breech Trial and the more recent PREMODA study from centers in France and Belgium:
These results confirm the findings of recent studies [7–11] that vaginal delivery of breech presentations is not accompanied by increased neonatal morbidity and mortality, as reported by Hannah et al. [1]. The difference in results can be explained by the differences in levels of experience and selection criteria. For example, pelvimetry was only performed in 10% of cases in the study by Hannah et al.; this percentage reached 82.5% for the planned vaginal deliveries in the PREMODA study [7] and 95.3% in the present study. Moreover, 21.4% of the vaginal breech deliveries in the study by Hannah et al. were performed by obstetricians in training or inexperienced midwives. In the present study, an anaesthetist and an obstetrician with at least 5 years of experience were present in the delivery room. The PREMODA study found that specific manoeuvres were necessary in 34.4% of breech deliveries, including 13.4% for retention of the aftercoming head [7]. In the present study, 11.3% of deliveries required forceps and there were no cases of cervical head entrapment.

The most fascinating part of the article came at the end of the discussion section, where the authors hypothesize that increased patient and care provider confidence in the safety of vaginal breech birth explain the rise in vaginal breech birth rates. Emphasis mine:
This study found an increase in the percentage of successful vaginal delivery of breech presentations from 24% in 2000 to 38% in 2008. This increase cannot be related to more favourable pelvic-tobiparietal comparisons, as this rate was similar before (77%) and after (72%) implementation of the protocol. Given that there were no changes in practice for breech deliveries except for implementation of this protocol, it is hypothesized that the reduction in the caesarean rate from 76% in 2000–2004 to 61.5% in 2004–2008 was due to practitioners’ increasing confidence in the safety of vaginal delivery. Moreover, the confidence of both practitioners and women appears to be bolstered by the systematic checking of ‘objective margins of security’ related to fetal biparietal diameter before allowing vaginal delivery. Finally, the reduction in the caesarean rate for breech delivery was part of an overall decrease in the caesarean rate in the authors’ department during this period (from 22% in 2000 to 17% in 2008). It was not possible to determine which aspects of the protocol were essential to increase the number of vaginal deliveries without increasing neonatal complications. The rate of refusal of vaginal delivery by women decreased from 19.3% in 2005 to 4.8% in 2008 (data not shown). This indicates that acceptance of the protocol also reassured the women, probably mediated by the physicians’ increased confidence. The trend since 2004 was confirmed in 2009, when more than 50% of breech presentations at the hospital were delivered vaginally.

The French hospital's protocol is similar to the 2009 SOGC guidelines on vaginal breech birth. Here is a summary of the Canadian guidelines for vaginal breech birth:
  • Baby is frank or complete with a flexed or neutral head attitude
  • No cord presentation, pelvic abnormalities, fetal growth restriction, or macrosomia
  • Baby's EFW is between 2500-4000g; EFW should be done within 10 days of onset of labor
  • Continuous electronic fetal heart monitoring is preferable in the first stage and mandatory in the second stage of labor
  • The HCP must be experienced in vaginal breech birth; an experienced OB should also be present to supervise other HCPs. HCP skilled in neonatal resuscitation should also be present at time of birth
  • Passive 2nd stage of up to 90 minutes, followed by an active 2nd stage of 60 minutes

Interestingly, the SOGC does not recommend radiographic pelvimetry. The guidelines note: "Clinical pelvic examination should be performed to rule out pathological pelvic contraction. Radiologic pelvimetry is not necessary for a safe trial of labour; good progress in labour is the
best indicator of adequate fetal-pelvic proportions."

The SOGC also rigorously supporis a woman's right to informed consent & refusal: "Women with a contraindication to a trial of labour should be advised to have a Caesarean section. Women choosing to labour despite this recommendation have a right to do so and should not be abandoned. They should be provided the best possible in-hospital care." 

Email me if you'd like a copy of the study! 

S. Michel, A. Drain, E. Closset, P. Deruelle, A. Ego, D. Subtil. Evaluation of a decision protocol for type of delivery of infants in breech presentation at term. European Journal of Obstetrics &amp; Gynecology and Reproductive Biology. 158 (2011) 194–198.

Relevant references: 
[1] Hannah ME, Hannah WJ, Hewson SA, Hodnett ED, Saigal S, Willan AR. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Term Breech Trial Collaborative Group. Lancet 2000;356:1375–83.
[7] Goffinet F, Carayol M, Foidart JM, et al. Is planned vaginal delivery for breech presentation at term still an option? Results of an observational prospective survey in France and Belgium. Am J Obstet Gynecol 2006;194:1002–11.
[8] Uotila J, Tuimala R, Kirkinen P. Good perinatal outcome in selective vaginal breech delivery at term. Acta Obstet Gynecol Scand 2005;84:578–83.
[9] Krupitz H, Arzt W, Ebner T, Sommergruber M, Steininger E, Tews G. Assisted vaginal delivery versus caesarean section in breech presentation. Acta Obstet Gynecol Scand 2005;84:588–92.
[10] Alarab M, Regan C, O’Connell MP, Keane DP, O’Herlihy C, Foley ME. Singleton vaginal breech delivery at term: still a safe option. Obstet Gynecol 2004; 103:407–12.
[11] Vendittelli F, Pons JC, Lemery D, Mamelle N. The term breech presentation: neonatal results and obstetric practices in France. Eur J Obstet Gynecol Reprod Biol 2006;125:176–84.


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