The Term Breech Trial was an international randomised controlled trial from 121 hospitals in 26 countries which reported that a policy of planned vaginal delivery for selected breech presentations at term was associated with a higher rate of perinatal mortality and neonatal morbidity compared with a planned CS4. It found no differences in maternal mortality or morbidity between the two arms of the study. The publication of the Trial in the Lancet in 2000 led quickly to a series of professional guidelines advocating elective CS for breech presentation at term and to a further escalation of CS rates5,6. As a result, in many maternity units in developed countries only about one in ten babies presenting by the breech at term are now delivered vaginally. In some cases of vaginal breech delivery labour is so advanced there is not time to undertake a CS, although a CS had been planned.
The Term Breech Trial, however, was seriously flawed1,7. In particular, some of the adverse perinatal outcomes were in cases which should have been excluded from the study. Furthermore, the details published of the adverse fetal outcomes were limited and were not analysed by parity or previous CS. More detailed scrutiny shows that the risks of an adverse fetal outcome was remarkably low in multigravidas who were randomised to a planned vaginal delivery in a trial that included hospitals from both developed and developing countries1. Soon after new international guidelines were published, the long-term clinical outcomes of the Trial were reported which found no difference between the two arms of the trial in terms of morbidity or mortality "in contrast to our earlier report"7,8. A secondary analysis from the Trial showed that the risks were higher if the CS was performed late in labour, and highest if the baby was delivered vaginally1. The intrapartum factors that were associated with higher fetal risk included augmentation of labour and/or prostaglandins (p<0.01), the duration of the second stage of labour (p<0.001) and birth weight (p=0.02). In the planned vaginal birth group, 49.8% had labour augmented, which is surprisingly high. This all suggests that the fetal risks of breech presentation are more strongly associated with labour than with the mode of delivery.
The lack of discernment in rushing to alter clinical practice in response to the Term Breech Trial has had consequences that received little consideration in 2000. The increase in CS for breech presentation in the index pregnancy has meant that there has been an increase in repeat CS, particularly as the number of women in developed countries undergoing a trial of labour after one prior CS has also plummeted dramatically. The increase in CS rates in turn increases the number of catastrophic obstetric complications such as uterine rupture and peripartum hysterectomy9,10. Well-intended attempts to improve fetal outcomes with breech presentation may have come at a cost for the mother's long-term reproductive health, as well as increasing the financial costs of providing maternity care due mainly to the increased length of stay associated with CS9.
Even if a CS is planned for all cases of breech presentation at term, some women deliver vaginally. In the Trial, only 90% of planned CS had a CS. A downside of the changes in obstetric practice has been the loss of clinical skills and experience among obstetricians in performing a vaginal breech delivery at term, which also compromises their ability to deliver a breech presentation either in the setting of a preterm labour or after vaginal delivery of the first twin. This loss of clinical skills will be exacerbated as obstetricians who trained before 2000 retire from labour ward duties. As a priority we now need to introduce simulation training for obstetricians in Ireland to teach vaginal breech delivery techniques, as has been necessary in other developed countries7. Fourteen years on, an editorial in The Lancet recognises the unintended serious consequences of the Trial, particularly in low-resource settings10. The authors believe that the increase in CS for breech presentation at term is dangerous, unnecessary and needs to be reversed10. They urge the global health community to consider the unintended, serious consequences of the policy changes following the 2000 publication in The Lancet, including the impact on already over-stretched maternity services.
The ‘knee-jerk’ response of the national organisations of obstetricians to the original study should also lead us to reconsider how we respond in general to the publication of clinical obstetric papers in high-impact general medical journals, and the influence they have had in changing the face of contemporary maternity care globally5,6. It highlights the risks of unquestioned international consensus, where individual errors of clinical judgement may be superseded by collective errors of judgement on a grand scale, potentially causing harm to large numbers of patients1.
*George Bernard Shaw was born at home on 26 July 1856 by vaginal breech delivery conducted by the Master of the Coombe Lying-In Hospital, Dr John Ringland. Shaw subsequently won the Nobel Prize for Literature in 1925 and an Academy Award (Best Screenplay) for the film Pygmalion in 1939. He died in England at the age of 94 in 1950.
MJ Turner, PJ Maguire
Department of Obstetrics and Gynaecology, UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital, Dublin 8
Email: [email protected]
References
1. Turner MJ. The Term Breech Trial: Are the clinical guidelines justified by the evidence? J Obstet Gynaecol 2006; 26: 491-94.
2. Toivonen E, Palomäki O, Huhtala H, Uotila J. Selective vaginal breech delivery at term - still an option. Acta Scand Gynecol Obstet 2012; 91: 1177-83.
3. Alarab M, Regan C, O'Connell MP, Keane DP, O’Herlihy C, Foley ME. Singleton vaginal delivery at term: still a safe option. Obstet Gynecol 2004; 103: 407-12.
4. Hannah ME, Hannah WJ, Hewson SA, Hodnett ED, Saigal S, Willan AR for the Term Breech Trial Collaborative. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Lancet 2000; 356: 1375-83.
5. American College of Obstetricians and Gynecologists (ACOG). Mode of term singleton breech delivery. Obstet Gynecol 2001; 98: 1189-90.
6. Royal College of Obstetricians and Gynaecologists (RCOG). The management of breech presentation. RCOG Green Top Guidelines: Guideline 20. London 2001.
7. Lawson GW. The term breech trial ten years on: primum non nocere? Birth 2012; 39: 3-9.
8. Whyte H, Hannah ME, Saigal S, Hannah WJ, Hewson S, Amankwah K et al. and the Term Breech Trial Collaborative Group: Outcomes of children at 2 years after planned cesarean birth versus planned vaginal birth for breech presentation at term: the international randomized Term Breech Trial. Am J Obstet Gynecol 2004; 191: 864-71.
9. Grivell RM, Dodd JM. Short- and long-term outcomes after cesarean section. Expert Rev Obstet Gynecol 2011; 6: 205-15.
10. Van Roosmalen J, Meguid T. The dilemma of vaginal breech delivery worldwide. Lancet 2014; 383: 1863-64.