4 October, 1999
Obstetrics Report gives New Zealand picture of birth interventions
THE first nation-wide report on trends of birth interventions in New Zealand was today released by the Ministry of
The Ministry's senior advisor of health professionals, Dr John Marwick, said the report would be a useful tool for
development of obstetric services in New Zealand.
"The report presents information gathered from hospitals by the New Zealand Health Information Services. It uncovers
trends of obstetric procedures over the ten years from 1July 1988 to 30 June 1998 and shows a marked increase in medical
interventions used during birth."
Inductions have risen from 7 for every 100 births in 1988 to about 22 per 100 last year. Caesarean section rates
increased from 11.7% of births to 18.2%. Instrumental vaginal deliveries (forceps and vacuum extractions) stayed fairly
constant (11.8% to 11.1%) The number of episiotomies appears has dropped. Epidural analgesia has risen to 24.1%. This
procedure was not recorded at all until 1994 but rose from 15% in 1995.
"The rise in caesarean sections and inductions is an international phenomenon. Analysis of the data suggests that a
significant part of the rise is responding to women's expectations rather than clinical need.
"All the procedures are less common in Maori, Pacific Islanders and women from deprived areas. For example epidural
analgesia was performed in about 14% of Maori women compared to 25% of non-Maori.
"If these procedures were being undertaken purely on clinical need then we might expect higher rates in Maori, Pacific
Island women and those from more deprived areas. The reverse is true, so at least some of the procedures are being done
for reasons other than clinical need.
"All obstetricians realise the heavy implications of further medical complications that inductions and caesarean
sections can lead to, which in turn can mean more expensive care for the mother and child. On the other hand intervening
too little may also carry with it unnecessary risk.
"The crucial question now is what do these figures mean for New Zealand women? Is this rate of intervention necessary?
If it is higher than necessary to achieve good results then should we be spending our health dollars elsewhere - perhaps
to improve outcomes for those with greatest need?
"It is a balance between intervening in births to ensure safe outcomes for women and babies, and allowing nature to
take its course.
"We need to ensure we get the balance right," said Dr Marwick
"This report gives a clear lead as to where discussion on this issue should be directed. It's an excellent resource
which can be used to improve services which can benefit New Zealand women."
For more information contact: Sue McCabe, Media Advisor, ph: 04-496-2483, pager: 025 495 989 Internet address:
1. Mr Rob Buist, Consultant Obsetrician & Gynaecologist, National Women’s Hospital
2. Dr Linda Batchelor, Consultant Obsetrician & Gynaecologist, Auckland Obstetrics Centre
3. Ms Phillippa Howden-Chapman, Researcher, Wellington School of Medicine
Key facts and figures
Between 1988 and 1998:
Caesarean Section rates rose from 11.7% of births to 18.2%, inductions rose from 7.0% to 22.1%, instrumental vaginal
deliveries (forceps and vacuum extractions) stayed fairly constant (11.8% to 11.1%), episiotomies appear to have fallen
(13.2% to 6.4% of births), epidural analgesia has risen rapidly to 24.1% (not recorded at all until 1994 but rising from
15% in 1995).
Further analysis of combined data from the two most recently reported years (1 July 96 - 30 June 98): a steady increase
in the rate that women have Caesarean sections as they get older the increase is more marked for arranged than for
emergency Caesareans and about half of the increase in arranged operations are for women who have already had at least
one Caesarean all procedures are performed less frequently in Maori and Pacific Island women (e.g. epidural analgesia
was performed in about 14% of Maori women compared to 25% of non-Maori) all procedures are performed less frequently in
women from more deprived areas (e.g. epidural analgesia was performed on 17% of women from most deprived areas compared
to 31% in those from least deprived areas).
The trend towards increasing rates of Caesarean sections has previously been described in New Zealand and is common to
several other countries. Our national rate in 1995 (15%) was very close to the UK?s national rate (the latest data we
have from Britain). The United States had a rate of 20.8% in 1997 compared to our 18.2% (a reduction from the very high
rates of ten years ago - 22.8% in 1989). There is evidence to suggest that clinical outcomes for women and babies can be
at least as good with rates of Caesarean Section considerably lower than 17.6%. Rates of 12% have been quoted
internationally as being compatible with good clinical results (South Auckland has a rate of 12.5%) and the US
Department of Health and Human Services has a goal of 15% by the year 2000.
The evidence from the current report suggests that the increasing rates are not driven solely by clinical necessity.
Maori, Pacific Island, and women from more deprived areas might be expected to have higher rates of conditions such as
smoking, diabetes, poor nutrition and poor antenatal care - all conditions that could predispose to a greater clinical
need to intervene. However, since it is these very groups who have the lower rates, it is likely that other factors such
as women's expectations, perceptions and requests are playing a large part.
The report documents a very steep rise in induction rates in the July 95 - June 96 year but this is thought to be partly
explained by changes in coding practice. Nevertheless, we now have a national rate of 21.5%. The rate reported from the
US is 18.4% in 1997; though these figures have been shown to be under-reported. Inductions, like other procedures, are
less common in Maori, Pacific Island and women from more deprived areas. Like Caesarean sections, these differences
cannot be explained by clinical need. While some increase in inductions may be justified by changes in what is
considered to be best evidence-based practice, this does not explain our overall high levels and the even higher rates
in some units. Again there are issues for discussion at the professional and provider level.
Instrumental vaginal deliveries
Rates for forceps and vacuum extraction (Ventouse) deliveries have declined very slightly over the 10 year period from
12.4% to 11%. US national data show a steady rate at about 9%. Both here and in the US there is a tendency for Ventouse
deliveries to rise in frequency while forceps decline. There is evidence that Ventouse carries less risk of damage to
the mother and this may explain its increasing use.
The report questions the accuracy of the figures for rates of episiotomy (a minor surgical procedure involving cutting
the woman’s perineum to allow the baby to be delivered more easily). However, even if the actual rates are somewhat
higher than reported, it is likely that the downward trend in rates is real (from 13.2% to 6.4%). Given the discomfort
and morbidity associated with the procedure, a drop in its frequency would generally be considered a positive result.
Epidural analgesia The data on epidural analgesia (a spinal injection to kill the pain of labour) shows that the
procedure was not recorded before June 1994 (although it was perfomed). Since then, however, there has been a rising
rate until the present national rate of 24% with some hospitals having closer to 40%. Information gathered by some
hospitals internally shows an even higher rate than that (e.g. 57% for Wellington Women's Hospital in 1997).
Availability of personnel skilled in the procedure (mostly anaesthetists) tends to be the limiting factor in some places
where the demand is not sufficient to warrant a dedicated obstetric anaesthetic service (or, conversely, availability of
such a service tends to stimulate demand). The report shows that epidurals are a very considerably more common procedure
in women who are neither Maori nor Pacific women and in those from least deprived areas.