Australia: the healthiest country by 2020
National Preventative Health Strategy – the roadmap for action

Key action area 7: Address maternal and child health, enhancing early life and growth patterns

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The case for prevention

The importance of maternal and child health in ensuring a healthy start to life is outlined in Chapter 1. There is a growing realisation and a substantial body of evidence highlighting the important links between maternal health and subsequent child health.

The epidemiological and experimental evidence supports a relationship between growth and development during foetal and infant life, and health in later years, noting two major implications:

‘First, it reinforces the growing awareness that investment in health and education of young people in relation to their responsibilities during pregnancy and parenthood is of fundamental importance. Secondly, any rational approach to healthcare should embrace a life course perspective.’[166]

These considerations have been recognised by WHO in consultations on diet, nutrition and chronic disease:

‘The outcome of a pregnancy must be considered in terms of maternal and neo-natal health, the growth and cognitive development of the infant, its health as an adult, and even the health of subsequent generations.’[63]

The evidence for this paradigm has come through numerous epidemiological studies of men and women in middle life, who have accurate birth weight records. Typical of these studies is the UK study of individuals from Hertfordshire, used by the Barker group.[167] Such studies provide evidence for the association of low birth weight and increased risk for hypertension, type 2 diabetes, metabolic syndrome, depression, cardiovascular diseases and mortality. As obesity prevalence is highest in low-income populations, intensive efforts will be required in disadvantaged communities.

A baby’s growth rate in utero and beyond is, in part, determined by parental factors, especially with regard to the mother’s diet, and what and how she feeds her baby, as well as other environmental factors (for example, smoking and alcohol intake), and potentially dietary toxins. Conditions in early life may continue to have an impact on health risks in adult life, illustrating one aspect of the intergenerational component of obesity.

There is also evidence that the period soon after birth is a time of metabolic plasticity. Factors in the environment, such as nutrition, can have long-lasting consequences in that they appear to set the baby on a particular developmental trajectory. While there is less evidence of a direct link between birth weight and obesity, weight gain in early life appears to be critical.

There are serious adverse effects of overweight during pregnancy, with the risk of complications increased for both mother and baby.[168] Obstetric risk increases with BMI among overweight and obese women.[169] Therefore, programs targeting pregnant women that cover healthy eating, physical activity and maintaining a healthy weight could enhance obstetric outcomes and reduce healthcare costs of obesity-related increases in maternal and neo-natal morbidity.
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Pregnancy

The intrauterine environment influences the risk of developing type 2 diabetes. Hyperglycaemia in pregnancy is associated with an increased risk of childhood obesity.[170] More research is needed to determine whether Gestational Diabetes Mellitus (GDM) may be a modifiable risk factor for childhood obesity.[171]

There is increasing evidence that the presence of obesity and/or type 2 diabetes in the mother can be associated with the development of obesity and/or type 2 diabetes in the child in later life. The offspring of diabetic pregnancies are often large and heavy at birth, developing obesity in childhood and at high risk of developing type 2 diabetes at an early age.[172] Such individuals have lower insulin secretion than similarly aged offspring of non-diabetic pregnancies.[173] A substantial part of the excess risk of diabetes in the offspring of diabetic pregnancies appears to be the result of exposure to the diabetic intrauterine environment. Among offspring born to mothers before and after the development of type 2 diabetes, those born after the mother developed diabetes have a three-fold higher risk of developing diabetes than those born before.[174] The enhanced risk among the offspring from diabetic pregnancies among such women is therefore the result of intrauterine programming that has long-term effects on the child in later life.

Breastfeeding and nutrition in childhood

Breastfeeding and early growth patterns provide the only period in which there is clear evidence to support the concept of a critical period of development associated with long-term consequences. Other stages of childhood, however, may offer good opportunities to modify behaviour. For example, there is limited evidence that behaviours such as liking fruit and vegetables can be established in early childhood.[175]

Breast-fed babies show slower growth rates than formula-fed babies, and this may contribute to the reduced risk of obesity later in life shown by breast-fed babies.[176] Observational studies suggest a longer duration of breastfeeding to be associated with a decrease in the risk of overweight in later life. As a result, in Europe and the United States high priority has been placed on research strategies investigating the effects of breastfeeding to prevent the development of obesity.[177-180]

In addition to the protective role breastfeeding may have in several chronic diseases, breastfeeding (including delaying the introduction of solids until babies are six months old) plays an important role in helping to prevent obesity in children.[181] This has been attributed to physiological factors in human milk as well as feeding and parenting patterns associated with breastfeeding. Weaning practices are also thought to be important, given the association between the characteristic weight gain seen in early childhood at approximately five years of age (early adiposity rebound) and later obesity.[182, 183]

The proportion of children receiving breast milk declines steadily with age.[184] While the proportion of Australian infants ever breast-fed was around 86–88% between 1995 and 2005, in 2001 less than half (48%) of all infants were receiving any breast milk at the age of six months, and none were being exclusively breast-fed.[181]
In 2001, the proportion of Australian children receiving breast milk was higher among more highly educated and older mothers (aged over 30 years).[184] Indigenous mothers in non-remote areas appear to be less likely to initiate and continue breastfeeding than other Australian mothers.[181]

There is a need to ensure the development of targeted interventions to improve maternal and child health among low SES and Indigenous women, as well as for younger and less educated mothers, particularly in regard to increasing levels and duration of breastfeeding.

The national toll-free breastfeeding helpline was recently upgraded (March 2009)[185] to provide 24-hour support and breastfeeding information through Australian Government funding. Funding has also been allocated to providing training for health professionals and research to support breastfeeding, including barriers and enablers to breastfeeding, indicators of breastfeeding rates and the development of dietary guidelines for pregnant and breastfeeding women.[186]
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It is recognised that the Taskforce should work with other relevant groups to ensure the implementation of programs in maternal and child health that are likely to deliver benefits in relation to obesity prevention.

Action 7.1
Establish and implement a national program to alert and support pregnant women and those planning pregnancy to the ‘lifestyle’ risks of excessive weight, insufficient physical activity, poor nutrition, smoking and excessive alcohol consumption.

Action 7.2
Support the development and implementation of a National Breastfeeding Strategy in collaboration with the state and territory governments.

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