Anti-caesarean drive “misguided”

A LEADING gynaecologist has warned that the “misguided” drive to reduce caesarean section rates may be putting women and their babies at risk of avoidable injury and death.

Professor Hans Peter Dietz, professor of obstetrics and gynaecology at Sydney Medical School Nepean, University of Sydney, told MJA InSight that in the past 10 years, performance indicators for obstetric services had shifted away from perinatal and maternal morbidity and mortality towards the caesarean section rate, with “peculiar flow-on effects”.

Professor Dietz said the potential fallout included increasing rates of maternal pelvic floor tears from forceps deliveries, postpartum haemorrhages as a result of long second-stage labours, and uterine ruptures in vaginal births after previous caesarean deliveries.

The outspoken gynaecologist noted that while countries such as Denmark, Sweden and Germany had almost completely abandoned forceps in favour of vacuum extraction, their use was growing in parts of Australia, following a similar pattern to the UK.

He said that in NSW, forceps-assisted deliveries in public hospitals accounted for 4.3% of births in 2012, up from 3.1% in 2008 — a trend Professor Dietz linked to political pressure to allow women to labour for longer, citing NSW Health’s “Towards Normal Birth” policy directive. (1) (2)

“Due to the rise in forceps rates in NSW, about 1000 additional women may by now have suffered avoidable, often incurable pelvic floor trauma”, Professor Dietz said, noting that forceps doubled the risk of trauma to the levator ani and anal sphincter.

“This is highly clinically relevant, putting women at risk of later prolapse and incontinence”, he said. “We can no longer ignore this particular outcome of childbirth.”

Professor Dietz also raised concern about the growing enthusiasm for vaginal birth after caesarean section (VBAC), suggesting the risks may sometimes be downplayed.

He cited a recent study of VBAC at Sydney’s St George Hospital, in which 103 caesareans were avoided but two babies had died. The first death followed uterine rupture during postdates oxytocin induction, while the second was a stillbirth in the VBAC group at 40+6 gestation. Neither death was mentioned in the study abstract or conclusion. (3)

Figures from the Royal Hospital for Women in Sydney had shown a trebling in the rate of blood transfusions associated with postpartum haemorrhage for vaginal birth between 2009 and 2010 (0.79% to 2.16%). (1)

Professor Dietz suggested this may be the result of another observed trend, of women being allowed to have longer labours. (4)

However, others have noted that there has also been a doubling in transfusions associated with caesarean section over the same period.

Professor Michael Permezel, president of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, agreed that arbitrary targets for caesarean section rates could be harmful.

“[They are] are unhelpful and risk an inappropriate loss of confidence by women in the care currently being provided”, he told MJA InSight.

“The tacit implication that caesarean section is unsafe or less desirable may be misleading”, he said, adding that both planned vaginal and elective caesarean births had good outcomes for Australian mothers and babies.

Professor Permezel said pelvic floor and anal sphincter trauma were “significant factors to be considered” in decisions of vaginal versus caesarean birth, and about instrumentation. However, he said there were “many other considerations of at least equal or perhaps greater importance for mother and baby”.

He defended the use of forceps, saying that vacuum extraction had been linked with a greater risk of neonatal injury and death through subgaleal haemorrhage.

A major spike in reported cases of subgaleal haemorrhages occurred in NSW in 2012, with nine cases that year alone, compared with a total of four in the preceding 6 years. (5)

Dr Amanda Henry, an obstetrician at Sydney’s St George Hospital and a coauthor of the St George study, agreed the deaths in the VBAC group would not have occurred had the women undergone elective repeat caesarean at the usual time.

In view of the risks, Dr Henry supported an editorial accompanying the study, which argued VBAC was not a promising strategy to reduce caesarean delivery rates. (6)

However, Dr Henry argued that there remained a place for VBAC in sociodemographic areas where large families were common and “women undergoing a third, fourth or fifth caesarean” was a concern, given the risks of ectopic pregnancy, morbidly adherent placenta, surgical injury and hysterectomy rose with each subsequent caesarean.

1. NSW Health 2014: NSW Mothers and babies 2012
2. NSW Health 2010: Maternity - Towards Normal Birth in NSW
3. ANZJOG 2014; Online 30 July
4. RANZCOG O&G magazine 2014; 3: 62-65
5. Clinical Excellence Commission 2014: Vacuum Assisted Births – Are We Getting it Right?
6. ANZJOG 2014; 54: 295-297

(Photo: Antonia Reeve / Science Photo Library)