Cesarean trends

Leung and colleagues raise 3 issues: 1) that my conclusions concerning the protective effect of cesarean section for anal incontinence were based upon the article by Eason and colleagues,¹ 2) that concerns about the detrimental effect of cesarean birth on breast-feeding rates should carry greater weight with women than concerns about pelvic floor injury associated with vaginal birth, particularly assisted vaginal birth, and 3) a global epidemic of cesarean delivery currently exists and must be curbed.

In fact, Eason and colleagues' study did not find that cesarean section afforded any protective effect from anal incontinence. I took issue with this conclusion based on evidence from our own prospective study as well as from the work of other authors.² In a study involving 690 women, we found that forceps delivery was associated with a higher incidence of both flatal (RR 2.6) and fecal (RR 3.6) incontinence when compared to cesarean delivery. On the other hand, elective cesarean delivery appears to protect the anal continence mechanism by preserving muscle strength as well as anal sphincter size.³ Although occasional flatal incontinence is unlikely to have a significant impact on quality of life, fecal incontinence has serious sequella.⁴

Faced with a choice between a trial of forceps and cesarean delivery, women must weigh the risks and benefits of these alternatives. Modern cesarean delivery in controlled circumstances is a very safe procedure for both the mother and the fetus. Forceps delivery, on the other hand, while associated with a low risk of fetal trauma, has a significant maternal risk of both short- and long-term sequellae from pelvic trauma. Faced with the choice between cesarean and forceps delivery, would a woman consider a 16% increased risk of not breast-feeding associated with cesarean delivery to be more important than the absolute risks of 44% for flatal incontinence and 9% for fecal incontinence associated with forceps delivery? In a survey of British obstetricians, up to 31% opted for ceserean delivery when faced with a normal full-term pregnancy.⁵ Their reason for choosing cesarean delivery was fear of pelvic injury associated with vaginal delivery. Like these obstetricians, I suspect most women who were properly informed about the risks they face with forceps delivery would prefer cesarean delivery, despite the slight chance that it might influence their chances of breast-feeding.

Leung and colleagues cite the WHO's recommendation that accoucheurs should aim for an upper limit of 15% for cesarean delivery rates as an appropriate benchmark against which we should measure our own rates. The WHO rate, unfortunately, was chosen arbitrarily and was not based on science. Over the last 2 centuries, cesarean section has evolved from an operation performed after the mother died in an effort to save the infant, to an operation that often offers the best option to protect both the mother and the fetus. In many African countries, prolonged obstructed labour results in high rates of maternal mortality. For those women who survive, many experience the particularly morbid complication of vesicovaginal fistula. Access to good obstetric care and timely cesarean delivery could significantly reduce maternal mortality and morbidity in these countries. At a time when maternal and fetal mortality rates are the lowest in recorded history in the developed world (where cesarean delivery rates are higher), one should be cautious about equating cesarean section with the term epidemic, a term that carries significant negative connotations.

Scott A. Farrell Department of Obstetrics and Gynaecology Dalhousie University Halifax, NS