The term breech: vaginal or cesarean delivery?
The Term Breech Trial has been hailed for shining light on the murky question of how best to deliver term breech infants. But does it really?
Conclusion
Last year at LBJ General Hospital in Houston, we performed 97 vaginal breech deliveries. (The total number of breech deliveries at the institution for the year was 158, a 3% incidence.) Unfortunately, our experience differs dramatically from that of most practitioners, as the number of physicians able to safely vaginally deliver singleton breech fetuses continues to dwindle. In fact, the threat of litigation already may have rendered the mode-of-delivery question moot in the United States. Time and social conditions—not science—have changed the practice of obstetrics.
The questions we should ask ourselves are these: What will happen when a woman with a term breech fetus presents in advanced labor and a cesarean cannot be accomplished expeditiously? It happened in 59 cases in the trial, 5.6% of the planned-cesarean group. And what will happen when none of the attendants of such a patient has ever observed a vaginal breech delivery?
It will be a sad moment in the history of our specialty. We will replace the questionable 3% attributable risk of perinatal mortality or serious neonatal morbidity found in the study (the approximate difference between 5% and 1.6%) with a possible—or even probable—5% risk of major fetal jeopardy!
REFERENCES
1. Hannah ME, Hannah WJ, Hewson SA, Hodnett ED, Saigal S, Willan AR. for the Term Breech Trial Collaborative Group. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Lancet. 2000;356:1375-1383.
2. Hannah WJ, Allardice J, Amankwah K, et al. The Canadian consensus on breech management at term. JSOGC. 1994;16:1839-1858.
3. Albrechtsen S, Rasmussen S, Reigstad H, et al. Evaluation of a protocol for selecting fetuses in breech presentation for vaginal delivery or cesarean section. Am J Obstet Gynecol. 1997;177:586-592.
4. Diro M, Puangsricharern A, Royer L, O’Sullivan M, Burkett G. Singleton term breech deliveries in nulliparous and multiparous women: a 5-year experience at The University of Miami/Jackson Memorial Hospital. Am J Obstet Gynecol. 1999;181:247-250.
5. Chadha YC, Mahmood TA, Dick MJ, et al. Breech delivery and epidural analgesia. Br J Obstet Gynaecol. 1992;99:96-100.
6. Seeds JW. Malpresentations. In: Gabbe SG, Niebyl JR, Simpson JL, eds. Obstetrics. 2nd ed. London: Churchill Livingstone; 1991.
7. Brenner WE, Bruce RD, Hendricks CH. The characteristics and perils of breech presentation. Am J Obstet Gynecol. 1974;118:700-709.
8. Towner D, Castro MA, Eby-Wilkens E, Gilbert WM. Effect of mode of delivery in nulliparous women on neonatal intracranial injury. N Engl J Med. 1999;341:1709-1714.
Elective cesarean
The Term Breech Trial was supposed to be impossible. Before it was undertaken, the National Institute of Child Health and Human Development explored the feasibility of conducting such a trial in the United States and concluded it would not be workable to recruit sufficient numbers of patients in a reasonable amount of time.1
But Mary E. Hannah persevered. After a systematic review of the randomized and nonrandomized trials comparing outcomes after breech presentation at term,2 she and her colleagues hosted a consensus conference of Canadian obstetricians experienced in vaginal breech delivery in order to lay out guidelines under which a trial of labor might safely be conducted.3 Participants also reached an agreement on appropriate intrapartum management. These efforts became the backbone of the Term Breech Trial protocol.
Although it was several years in planning, the trial was not without some urgency. As its authors noted in a letter commenting on the feasibility of such a study: “We are concerned that time is running out to answer this question as those who are skilled and experienced in the technique of vaginal breech delivery are leaving clinical obstetric practice.”4
Like many of the clinicians who participated in the trial, I hoped the study would find no difference in fetal/neonatal outcomes between the 2 modes of delivery. Thus, I was somewhat disappointed when elective cesarean proved to be the safer treatment. Nevertheless, I believe the findings of the trial are highly robust. Any way you look at the data, there is an advantage to planned cesarean delivery.
The risks of vaginal delivery
The most feared complication of attempted vaginal breech delivery is entrapment of the aftercoming head, which can result from relative fetopelvic disproportion or from nuchal arms. Besides death and serious morbidity such as asphyxial injuries, clavicle fractures, and brachial plexus injuries, spinal cord injuries and maternal genital trauma may result. While these complications also may occur with cesarean delivery, most U.S. and Canadian obstetricians feel that the likelihood of difficult extraction and major trauma is lower with cesarean section. The results of the Term Breech Trial confirm this assumption.
