1st December 2017, Volume 130 Number 1466

Teresa Castro, Cameron Grant, Clare Wall, Michaela Welch, Emma Marks, Courtney Fleming, Juliana Teixeira, Dinusha Bandara, Sarah Berry, Susan Morton

Breastfeeding reduces the risk of child deaths and of infectious disease morbidity.1 Breastfeeding is associated with fewer dental malocclusions, higher intelligence quotient scores and a reduced risk of overweight and…

Subscriber content

The full contents of this page is only available to subscribers.

To view this content please login or subscribe


Although 97 percent of New Zealand children are breastfed initially, a large number are not being breastfed for as long as international guidelines recommend. New evidence from the Growing Up in New Zealand longitudinal study of more than 6,000 children and families (generalisable to the New Zealand national birth cohort) showed only one in six children achieved the World Health Organization-recommended six months of exclusive breastfeeding. One in eight achieved the recommendation of receiving some breast milk for two or more years. Duration of breastfeeding was also shown in the study to be associated with mothers’ age, ethnicity, education, number of children and whether the pregnancy was planned.



To describe breastfeeding initiation and duration, and demographic associations with breastfeeding duration within a representative sample of New Zealand infants.


In 6,685 singletons enrolled in the Growing Up in New Zealand cohort we described breastfeeding initiation (96%), any (94%) and exclusive (93%) breastfeeding (EBF) duration. We used adjusted relative risk (RR) and 95% confidence intervals (CI) to describe associations with breastfeeding duration.


Breastfeeding initiation occurred for 97%. Sixteen percent were EBF to age six months and 13% were breastfed to age 24 months. Exclusive breastfeeding for ≥4 months was less likely for children of mothers of Māori (RR=0.80, 95% CI 0.73–0.87), Pacific (0.90, 95% CI 0.83–0.98) or Asian (0.80, 95% CI 0.74–0.86) ethnicity. Children of mothers aged 20–29 years (1.24, 95% CI 1.04–1.49); ≥30 years (1.36, 95% CI 1.14–1); with a tertiary education (1.14, 95% CI 1.08–1.21); or planned pregnancy (1.14, 95% CI 1.08–1.21); and children with older siblings (RR=1.31, 95% CI 1.17–1.47) were more likely to be exclusively breastfed for ≥4 months. Children were more likely to be breastfed ≥6 months if their mother was aged 20–29 (1.26, 95% CI 1.10–1.45) or ≥30 years (1.40, 95% CI 1.22–1.61), had a tertiary education (1.11, 95% CI 1.06–1.59) or planned pregnancy (1.11, 95% CI 1.06–1.15), or if they had older siblings (1.04, 95% CI 1.00–1.08).


In New Zealand, most children are initially breastfed, however a large proportion did not receive the recommended duration of any or exclusive breastfeeding. Maternal age, education, parity and pregnancy planning identify children at risk of shorter duration of breastfeeding and EBF, and maternal ethnicity identifies children at risk of shorter EBF duration.

Author Information

Teresa Castro, Paediatrics and Growing Up in New Zealand, University of Auckland, Auckland; Cameron Grant, Paediatrics, Growing Up in New Zealand and Centre for Longitudinal Research—He Ara ki Mua; Clare Wall, Discipline of Nutrition and Dietetics, University of Auckland, Auckland;
Michaela Welch, Medicine, Boston University, United States; Emma Marks, Growing Up in New Zealand, University of Auckland, Auckland; Courtney Fleming, Auckland District Health Board, Auckland; Juliana Teixeira, Nutrition, University of Sao Paulo, Brazil; Dinusha Bandara, Growing Up in New Zealand, and Centre for Longitudinal Research—He Ara ki Mua, University of Auckland, Auckland; Sarah Berry, Growing Up in New Zealand, University of Auckland, Auckland;
Susan Morton, Growing Up in New Zealand, and Centre for Longitudinal Research—He Ara ki Mua, University of Auckland, Auckland.


Most importantly, we would like to acknowledge the children and the families who are part of the Growing Up in New Zealand study. We would also like to acknowledge the initial funders, in particular the New Zealand Ministry of Social Development, supported by the Health Research Council as well as the ongoing support from Auckland UniServices and The University of Auckland. We acknowledge all the members of the Growing Up in New Zealand team, including those members and managers of the operational, data, communications, community and quality aspects of the study. We thank the ongoing support and advice provided by our Kaitiaki Group and our national and international Scientific Advisory Group and we also acknowledge the members of the Morton Consortium responsible for planning and design of this study in the development phase. We thank Catherine Gilchrist for review of the manuscript.


Dr Cameron Grant, Paediatrics, University of Auckland, Grafton Road, Auckland 1142.

Correspondence Email


Competing Interests



  1. Victora CG, Bhal R, Barros AJD, et al. Breastfeeding in the 21st century: epidemiology, mechanisms, and lifelong effect. The Lancet. 2016; 387:475–87.
  2. World Health Organization: United Nations Children`s Fund. Global Strategy for Infant and Young Child Feeding. Geneva, Switzerland: World Health Organization; 2003.
  3. World Health Organization: United Nations Children`s Fund. Indicators for assessing infant and young child feeding practices: Part 1-Definitions. Geneva, Switzerland: World Health Organization; 2008.
  4. Organisation for Economic Co-operation and Development. Doing better for children. Organisation for Economic Co-operation and Development; 2009.
  5. World Health Organization. Global data bank on infant and young child feeding [online[, 2016. Available at http://www.who.int/nutrition/databases/infantfeeding/en/ Accessed 7 September 2016.
  6. Bosi ATB, Eriksen KG, Sobko T, et al. Breastfeeding practices and policies in WHO European Region Member States. Public Health Nutr. 2015; 19(4):753–64.
  7. Ministry of Health. 2008. Food and Nutrition Guidelines for Healthy Infants and Toddlers (Aged 0–2): A background paper (4th ed) – Partially Revised December 2012. Wellington: Ministry of Health.
  8. Ministry of Health. The health status of children and young people in New Zealand. Dunedin: New Zealand Ministry of Health, 2013.
  9. Rollins NC, Bhandari N, Hajeebhoy N, et al. Why invest, and what it will take to improve breastfeeding practices? Lancet. 2016; 387:491–504.
  10. Morton SMB,, Ramke J, Kinloch J, Grant CC, Atatoa Carr P, Leeson H, Chi Lun Lee A, Robinson E. Growing Up in New Zealand cohort alignment with all New Zealand births. Aust NZ J Public Health. 2014: Online; doi: 10.1111/1753-6405.12220
  11. Morton SMB, Atatoa Carr P, Grant CC, et al. Growing Up in New Zealand: A longitudinal study of New Zealand children and their families. Now we are Two: Describing our first 1000 days. Auckland: Auckland: Growing Up in New Zealand, 2014.
  12. Morton SM, Ramke J, Kinloch J, et al. Growing Up in New Zealand cohort alignment with all New Zealand births. Aust NZ J Public Health. 2015; 39(1):82–87.
  13. World Health Organization (1991) Indicators for Assessing Breast Feeding Practices. WHO/CDD/SER/91.14. Geneva:WHO.
  14. Wall CR, Brunt DR, Grant CC. Ethnic variance in iron status: is it related to dietary intake? Public Health Nutr. 2009; 12:1413–1421.
  15. Salmond C, Crampton P, Atkinson J (2007). NZDep2006 Index of Deprivation. Wellington. University of Otago.
  16. Gigerenzer G, Gaissmaier W, Kurz-Milcke E, Schwartz LM, Woloshin S. Helping Doctors and Patients Make Sense of Health Statistics. Psychol Sci Public Interest. 2007; 8(2):53–96. 
  17. Baby Friendly Hospital Initiative Hong Kong Association: United Nations Children`s Fund. The World Breastfeeding Trends Initiative (WBTi). Hong Kong, China; 2012.
  18. Robert E, Coppieters Y, Swennen B, Dramaix M. Breastfeeding duration: A survival analysis- Data from a Regional Immunization Survey. Biomed Research International. 2014; doi: 10.1155/2014/529790.
  19. Santorelli G, Petherick E, Waiblinger D, et al. Ethnic differences in the initiation and duration of breast feeding-Results from the Born in Bradford Birth Cohort Study. Paediatr Perinat Epidemiol. 2013; (27):388–92.
  20. Grifiths LJ, Tate AR, Desateux C and the Millennium Cohort Study Child Health Group. The contribution of parental and community ethnicity to breastfeeding practices: evidence from the Millennium Cohort. Int J Epidemiol. 2005; 34:1378–86.
  21. Grewal NK, Andersen LF, Sellen D, et al. Breast-feeding and complementary feeding practices in the first 6 months of life among Norwegian-Somali and Norwegian-Iraqi infants: the InnBaKost survey. Public Health Nutr. 2015; 19(4):703–15.
  22. Dubois L, Girard M. Social determinants of initiation, duration and exclusivity of breastfeeding at the population level: the results from the Longitudinal Study of Child Development in Quebec (ELDEQ 1998–2002). Can J Public Health. 2003; 94(4):300–5.
  23. Centers for Disease and Control. Breastfeeding Report Card- United States/2014. Atlanta: CDC, 2014.
  24. Baxter J, Cooklin AR. Which mothers wean their babies prematurely from full breastfeeding? An Australian cohort study. Acta Paediatr. 2009; 98:1274–7.
  25. Silvers KM, Frampton CM, Wickens K, et al. Breastfeeding protects against adverse respiratory outcomes at 15 months of age. Matern Child Nutr. 2009; 5:243–50.
  26. Schluter PJ, Carter S, Percival T. Exclusive and any breast-feeding rates of Pacific infants in Auckland: data from the Pacific Islands First Two Years of Life study. Public Health Nutr. 2006; 9(6):692–99.
  27. Ministry of Health. 2012. Report on Maternity, 2010.Wellington: Ministry of Health.
  28. Pitonyak JS, Jessop AB, Pontiggia L, Crivelli-Kovach A. Life course factors associated with initiation and continuation of exclusive breastfeeding. Matern Child Health J. 2016; 20:240–9.
  29. Haughton J, Gregorio D, Perez-Escamilla R. Factors associated with breastfeeding duration among Connecticut Special Supplemental Nutrition Program for Women, Infants and Children (WIC) participants. J Hum Lact. 2010; 26(3):266–73.
  30. Hromi-Fiedler A, Perez-Escamilla R. Unintended pregnancies are associated with less likelihood of prolonged breast-feeding: an analysis of 18 Demographic and Health Surveys. Public Health Nutr. 2006; 9(3):306–12.
  31. Taylor JS, Cabral HJ. Are women with an unintended pregnancy less likely to breastfeed? J Fam Pract. 2002; 51:431–6.
  32. Li R, Scanlon KS, Serdula MK. The validity of maternal recall of breastfeeding practice. Nutrition Reviews; 63(4):103–10. 
  33. Burhnham L, Buczek M, Braun N, Feldman-Winter L, Chen N, Merewood A. Determining length of breastfeeding exclusivity: validity of maternal report 2 years after birth. J Hum Lact. 2014; 30(2):190–4.
  34. Gillespie B, d ‘Arcy H, Schwartz K, Bobo JK, Foxman B. Recall of age of weaning and other breastfeeding variables. Int Breastfeed J. 2006; 9:1–4. 
  35. Agampodi SB, Fernando S, Dharmaratne SD, Agampodi TC. Duration of exclusive breastfeeding; validity of retrospective assessment at nine months of age. BMC Pediatrics. 2011; 14:80. doi: 10.1186/1471-2431-11-80.
  36. Greiner T. Exclusive breastfeeding: measurement and indicators. Int Breastfeed J. 2014; 20(9):18. doi: 10.1186/1746-4358-9-18.
  37. Abdel-Hady DM, El-Gilany A. Calculating exclusive breastfeeding rates: comparing dietary “24-hour recall” with recall “since birth” methods. Breastfeed Med. 2016; 11(10):514–8.
  38. World Health Organization: United Nations Children`s Fund. Global Nutrition Targets 2025- Breastfeeding Policy Brief. Geneva, Switzerland: World Health Organization; 2014.
  39. Perez-Escamilla, Sellen D. Equity in breastfeeding: where do we go from here? J Hum Lact. 2015; 31(1):12–4.


The downloadable PDF version of this article is only available to subscribers.

To view this content please login or subscribe