Proportion of women giving birth by caesarean section in New Zealand

When the term 'women giving birth' is used, the numbers presented are births and are the number of women giving birth during the calendar year (ie, from 1 January to 31 December). A woman who had twins or a multiple birth is counted as having had one birth. A woman who gave birth twice within the same calendar year is counted twice.
The number of births presented includes only live births recorded in the Maternity Collection (MAT) at any gestation, and where a birth has a registration or birth record reported in the National Minimum Dataset (NMDS). Where a birth has an equivalent death registration recorded in the New Zealand Mortality Collection, the birth is also excluded from the analysis.
Deprivation is derived according to the residence of the individual. Numbers and rates are presented by deprivation quintile, ranging from quintile 1 (least deprived) to quintile 5 (most deprived). Deprivation scores are based on the 2006 New Zealand Deprivation Index for women giving birth before 2010, on the 2013 Deprivation Index for women giving birth from 2010 to 2015 and on the 2018 Deprivation Index from 2016 onwards.

Assisted birth: vaginal birth, including assisted breech birth.
Assisted breech: an assisted vaginal birth in which a baby being born feet or buttocks first is delivered spontaneously as far as its umbilicus and is then extracted. It may include the use of forceps.
Breech birth: a vaginal birth of a baby where the buttocks or lower limbs precede the head.
Breech extraction: an assisted vaginal birth, performed by grasping the baby’s feet or buttocks before any part of the trunk is born and delivering by traction. It may include the use of forceps.
Caesarean section: delivery involving an operation through an abdominal incision.
Elective caesarean section: a caesarean section performed as a planned procedure before or following the onset of labour, where the decision to have a caesarean section was made before labour.
Emergency caesarean section: an unplanned caesarean section performed urgently for the health of the woman or baby, once labour has started.
Instrumental vaginal birth: vaginal birth requiring obstetric delivery assistance eg, forceps, vacuum extraction.
Spontaneous breech: the birth of a baby from a breech presentation without obstetric intervention to facilitate delivery, but which may include other obstetric procedures such as induction.
Spontaneous vaginal birth: birth of a baby without any obstetric delivery assistance to facilitate delivery; includes spontaneous breech birth (vaginal birth in which the baby’s buttocks or lower limbs precede its head). These births may include labour interventions such as induction or augmentation prior to delivery.

Each individual represented in the data is allocated to a single ethnic group, using the following priority system: Māori > Pacific peoples > Indian > Asian (excl. Indian) > Other > European. Individuals of European and of Other ethnicities are often grouped together and presented as being part of the 'European or Other' ethnic group due to small numbers in the ''Other' ethnic group.

Birth procedure type codes are only available for women giving birth at a maternity facility.
Women giving birth at home are assumed to have a spontaneous vertex (normal) delivery.
Women may have more than one birth procedure for each pregnancy so a priority system is used to allocate one procedure type per pregnancy.

While the data is collected for 'women' it is important to note that it actually includes all people who have given birth and that the data may include some transgender people.

From 1 July 2019, diagnoses codes are assigned using the 11th Edition of ICD-10-AM (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification) and procedure codes are assigned using the 11th Edition of ACHI (Australian Classification of Health Interventions) (Source: The Independent Health and Aged Care Pricing Authority).
Some maternity events (women giving birth in hospital and live babies born in hospital) are impacted by changes in the 11th Edition clinical coding standards, particularly place of birth and type of birth data. Therefore, this data may show variation due to the change in coding standards rather than a true increase.
The Primary Maternity Services Notice 2021 came into force on 29th November 2021, introducing changes to the terms and conditions on which maternity providers can claim for providing primary maternity services. This revokes the Primary Maternity Services Notice which came into effect on 1 July 2007 and its amendments.
There are underlying changes to the way some data are now captured (such as smoking status or breastfeeding and Well child referral). Also some metrics are no longer collected (such as height and weight at registration, which impacts on BMI calculation). It is important to consider these changes when comparing claims data pre and post November 2021.

At URL provided, under 'Labour and birth ' heading, select 'Download full datasets' and 'WGB_birth_type_table' file.

The National Maternity Collection collates data from three different sources to provide statistical, demographic and clinical information about women giving birth and live-born babies in New Zealand.
Data for the web tool was extracted from publicly funded maternity events recorded in Te Whatu Ora - Health New Zealand's National Maternity Collection on 12 May 2023.

To provide annual health statistics about women giving birth, their pregnancy and childbirth experience and the characteristics of live-born babies in New Zealand.

Population data for rate calculations was provided by Stats NZ