Birthweight of babies born in New Zealand

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.

BREASTFEEDING
Exclusive: the infant who has never, to the mother’s knowledge, had any water, formula or other liquid or solid food. Only breast milk (from the breast or expressed) and prescribed medicines (defined in the Medicines Act 1981) have been given to the baby from birth.
Fully: the infant has taken breast milk only, and no other liquids or solids except a minimal amount of water or prescribed medicines, in the past 48 hours.
Partial: the infant has taken some breast milk and some infant formula or other solid food in the past 48 hours.
Artificial: the infant has had no breast milk but has had alternative liquid such as infant formula, with or without solid food in the past 48 hours.

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.

The numbers presented only include live-born babies at any gestation. Babies resulting from a twin or multiple pregnancy are counted individually.
Each year, a small proportion of births are recorded in MAT without a birth status. These records are notably less complete than records for live births and are not included. The majority of these records are reported as planned homebirths but can also include unplanned homebirths and out-of-hospital births. From 2012 to 2021, the proportion of records where birth status was not reported ranged from 0.4 to 1.3% of total births in any given year. Te Whatu Ora is currently confirming information about these births. Where possible, records will be updated, and these changes will be reflected in future updates.

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 'Babies' heading, select 'Download full datasets' and 'baby_gest_BW_BF_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