Private obstetricians are facing questions over their role in the relentless rise in the number of mothers giving birth by caesarean, including those done purely for "maternal request".
More than a quarter of births nationally are by caesarean, but at Auckland District Health Board's National Women's service the latest rate, for 2015, is higher, at 36 per cent, including emergency caesareans. In 1992, it was 17 per cent.
But one private obstetrician, Dr Dereck Souter, is unrepentant.
What should be the driver is that the babies and mothers are in as good a condition and with as minimal trauma as possible
Women can choose where to give birth and when measured by where women live, Auckland's and Waitemata DHB's caesarean rates were 30 per cent in 2013, higher than the national rate partly because women in the two areas are on average older than elsewhere.
But it is the rate of caesareans among first-time mothers that is worrying some DHBs.
"It is of concern that at National Women's Health in 2015, 148 [first-time mothers] had an elective caesarean section for the indication of maternal request," officials say in a report.
This was 22 per cent - the leading reason - of first-timers' having elective or pre-labour caesareans, up from 16 per cent in 2012. Among second-time or later mothers the major driver of the caesarean rate is previous caesarean.
"The last two years, Auckland DHB has had significantly more low risk [first-time-birth] women have a caesarean section compared to similar facilities around New Zealand. It is possible it reflects the demographics of our women (older women, higher body mass index etc) or the other interventions in labour (induction of labour, epidural in labour).
"However, we also need to look at our model of care (few birth at a birthing centre, the role of private obstetrics) and to consider whether some of these caesareans were unnecessary."
The report urges health practitioners to be patient during inductions and the first two stages of labour, and suggests reviewing the reasons for caesareans in low-risk first-timers.
Counties Manukau DHB - where 23 per cent gave birth by caesarean in 2014 - says "earlier recourse" to the operation may be a factor in the reduction in its number of newborns suffering brain damage from oxygen deprivation during birth.
Souter, who also works part-time at National Women's, said its 2015 report showed the condition of babies immediately following birth was better if the lead maternity carer was a private obstetrician rather than an independent midwife.
And he discounted the idea that "maternal request" equated to "women saying, 'To fit in between my hair appointment and my lunch date I prefer to have the baby on that day'.
"I might have had one [like that] in my career. Most women have genuine reasons - pelvic floor concerns, sisters who have lost babies in labour, that would go down as 'maternal request', or a 45-year-old after years of infertility having her first baby and wanted to absolutely minimise the risk to her baby and her pelvic floor."
Caesarean section is a safe operation; a good option for women planning to have up to two children, but not for those planning to have three or more, Souter said.
There is no ideal caesarean rate, and the need differed between different age and ethnic groups. "What should be the driver is that the babies and mothers are in as good a condition and with as minimal trauma as possible."
Caesarean rate for first-time mothers
• 52% - of those booked with a private obstetrician
• 41% - National Women's high-risk team
• 31% - National Women's community team
• 29% - Independent midwife
Source: National Women's Health 2015 clinical report