Breastfeeding Prevalence During the First 3 Years: A New Zealand Study of Electronic Health Records

Breastfeeding has known health benefits and recommendations are to exclusively breastfeed for the first 6 months and continue to 2 years or beyond. While breastfeeding in early infancy has been previously estimated in New Zealand (NZ), these data are limited, and little is known about breastfeeding prevalence beyond the first 6 months, or how it varies between population groups.

Describe breastfeeding prevalence in NZ infants by age; and examine differences by infant, maternal and household factors.

Observational study using routinely collected breastfeeding data from 103,893 maternal-infant dyads in NZ between January 2023 and June 2024. Seven contacts occurred between the ages of 4-6 weeks and 2-3 years. Infant, maternal and household data were also collected at contacts.

The prevalence of 'any' breastfeeding declined from 85% at around 1 month to 12% by 28 months. The prevalence of exclusive/full breastfeeding was around 57% at 1-3 months and dropped to 32% by around 5 months. Breastfeeding prevalence was highest for those living in the least socioeconomically deprived neighbourhoods, those with comprehensive knowledge and service literacy, those with mothers aged >20 years, and those of MELAA or Asian ethnicity. Infant sex, first-time parenting status, and region appeared to have little impact on breastfeeding prevalence.

In NZ, the majority of infants are breastfed at 1 month; however, only 1 in 3 are exclusively/fully breastfed to the age recommended and overall breastfeeding prevalence declines over the first two years. Breastfeeding prevalence varies between ethnic and socioeconomic groups, suggesting that there may be areas for targeted intervention to support increased breastfeeding prevalence.