Kiwi babies aren't being breastfed for as long as international guidelines recommend, researchers have found.
A study published today in the New Zealand Medical Journal, drawing on data from more than 6000 single-born children from birth through to 2 years of age, found that while nearly all were exclusively breastfed initially, rates dropped to just over half by the time the child reaches 4-months-old.
"We found that 97 per cent of the children were breastfed initially, with one in six receiving only breast milk up to six months and one in eight receiving some breast milk to two years old," study co-author and Auckland paediatrician Professor Cameron Grant said.
The World Health Organisation recommends that breastfeeding begin within an hour of birth, is exclusive to six months and continues to two years and beyond, alongside appropriate complementary feeding from six months.
New Zealand's Ministry of Health and Plunket also encouraged mums to breastfeed exclusively until babies are around 6 months old.
The practice is considered crucial to help protect infants against colds, stomach bugs, infections and allergies, while also giving mums rest, saving them time and money, and even reducing risk of some cancers and bone disease.
"There is considerable evidence of the health and economic benefits that breastfeeding brings to families and society," Grant said.
"So while breastfeeding practices are affected by a range of individual and other factors, it's important that we plan and evaluate strategies to support, promote and protect breastfeeding in New Zealand."
Using the data collected by the University of Auckland's Growing Up in New Zealand study, the research also found that the percentage of children who were exclusively breastfed at age 6 months (16 per cent) was higher than that reported in 2011 from Plunket data (12 per cent).
Research co-author Dr Teresa Castro said 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.
"Mothers who identified their ethnicity as Maori, Pacific or Asian were less likely than European mothers to breastfeed exclusively for four or more months," she said.
"While mothers were more likely to breastfeed exclusively for at least four months and continue past six months if they were older than 20 years, had a tertiary education, had planned their pregnancy or if the child had older siblings."
To date, New Zealand breastfeeding data have been incomplete, with Maori and Pacific mothers under-represented.
But the Growing Up in New Zealand cohort was broadly representative of the New Zealand national child population in terms of ethnic and socio-economic diversity, providing the opportunity to describe breastfeeding duration in a way that reflects the country's make-up.
"The research is the first description of breastfeeding indicators in a New Zealand sample that is generalisable to the national birth cohort," Castro said.
Auckland mum: 'I've had a privileged experience'.
Jin Russell has exclusively breastfed Chester, 3, and Toby, 6 months, in line with official guidelines.
But the Auckland mum said she was in a fortunate position that many under-pressure parents weren't.
She credited Plunket and midwives at Auckland's Birthcare Maternity Hospital for "invaluable" advice that allowed her breastfeed Chester until he weaned himself off at 15 months.
Russell has also ensured baby Toby has been exclusively breastfed in his first six months.
"But I'm very conscious that I've had a very privileged experience, because a lot of my friends haven't had that and they've had to go back to work a lot earlier."
She said she had been lucky to be able to take maternity leave for as long she'd wished to.
"I like to follow the WHO guidelines, I just that think that a lot of mums, perhaps in developed countries, might find it really difficult because of the sort of factors that put pressure on mums to start formula earlier."
Paid parental leave is currently at 18 weeks, but the Government has just approved new policy increasing that to 22 weeks by July 1, 2018, and 26 weeks by July 1, 2020.
"And I suppose there might be mums who think, for their own wellbeing, that they need to have a break from breastfeeding from time to time, and that means giving the baby a bottle."
The study's authors said improving breastfeeding practices required supportive measures at different levels, including legal and policy directives, social support, women's employment conditions, access to healthcare, and skills to support breastfeeding.
Future studies would investigate barriers to breastfeeding initiation and duration, with the aim to developing interventions aimed at improving breastfeeding practices in New Zealand.