Obstetric interventions among private and public patients

Pregnant women in Australia who give birth in private hospitals have higher rates of operative delivery (caesarean sections, forceps procedures, and vacuum extractions) than those who use public hospitals. Do they need to have more caesarean sections? In this edition of the BMJ, Roberts and colleagues (p 137) examine the risk profiles of these two populations among women having babies in New South Wales, Australia.¹ They found that similar rates of women were classified as low risk (48% in private hospitals and 49% in public). Within these low risk groups, private patients were more likely to be 30-34 years old, but the proportion of women classed as being at low risk was the same in each group. The authors, therefore, reasonably argue that this counters the commonly held view that the reason for higher rates of caesarean sections in private patients in Australia is because women at higher risk of complications in pregnancy are more likely to take out private insurance for pregnancy care.

In this large, population based study of 170 000 women they then compared the obstetric management of these two groups of low risk women. Private patients who were classed as low risk and who were having their first baby had significantly higher rates of caesarean section before and during labour (16.4% v 10%). The authors also point out that in addition to this higher rate of caesarean delivery, this group of private patients also had double the rates of forceps procedures and vacuum extractions than public patients (34% v 17%). Private patients were also more likely to have had labour induced or augmented with oxytocin (49% v 35%), twice as likely to have had an epidural anaesthetic (51% v 25%), and more likely to have had an episiotomy (47% v 29%). The authors do not report on perinatal outcomes, but they assume that in these low risk populations there are no differences in perinatal mortality or morbidity associated with these practices.

It might be expected that the group that had higher rates of caesarean sections in order to avoid difficult or complicated births would have had lower rates of operative vaginal delivery. These findings, therefore, need to be analysed, particularly in light of concern about the association between pelvic floor damage and operative vaginal delivery and episiotomy.²

A recent report by the Australian government into childbirth procedures said that private practice in obstetrics encourages operative intervention for comparatively minor indications, not so much because doctors get paid more for these interventions but because it takes less time to carry out a caesarean section than supervise a difficult labour. It is also thought that caesarean sections are carried out to avoid litigation.³ There is little reliable evidence to guide practitioners on whether higher rates of caesarean section are associated with better outcomes or increased satisfaction. Some women and their obstetricians support the idea of caesarean section being performed on request, whereas consumer advocates refer to the “caesarean section industry” and argue that the procedure disrupts bonding between mother and baby and devalues the empowering nature of normal birth.⁴,⁵

The best way of resolving this uncertainty would be to obtain reliable evidence to guide clinicians, but randomised trials are unlikely to be feasible. Large cohort studies using long term follow up of women after childbirth could help resolve important questions about the effects of caesarean sections and different forms of vaginal delivery.⁶

It is also probable that the pressures of private practice, which are thought to result in higher caesarean rates, may also in part explain the higher rate of operative vaginal interventions; these may be of even greater concern than the caesarean rate.

Defenders of higher rates cite observational evidence that caesarean sections (particularly elective) reduce the risk of damage to the pelvic floor caused by vaginal birth and the long term sequelae of urinary and faecal incontinence.² If there were no long term adverse sequelae from a caesarean section (and this is far from certain) private patients might well benefit from these higher caesarean rates. However, the evidence suggests that some women are harmed by higher rates of forceps procedures and from routine episiotomy. The Cochrane systematic review on episiotomy concludes that “there is clear evidence to recommend restrictive use of episiotomy.”⁷ Another Cochrane review also indicates that vacuum extraction is associated with less perineal trauma than forceps delivery.⁸

Obstetricians and midwives in both settings (private and public hospitals) should continue to explore the evidence underpinning their practice and to integrate the best available evidence when negotiating the complexities of decision making. Meanwhile, women need to be advised that a caesarean section is not a panacea. These apparently unduly high rates of operative vaginal delivery in private practice could be reduced, with benefit for mothers, by devising system changes that relieve the pressures of private practice in obstetrics. These changes should help obstetricians reduce their use of interventions in the process of vaginal delivery that are not supported by reliable evidence.

Papers p 137