Size matters

Every child grows and develops at a different rate, and most will do so normally if they receive good nutrition and are not sick for a long time. But what is ‘normal’ growth and how is it measured?

Charting growth

Growth assessment is an essential component of the clinical assessment of a child, says Dr Catherine Choong, President of the Royal Australasian College of Physicians’ Paediatrics and Child Health Division, consultant Paediatric Endocrinologist; and Clinical Professor, Paediatric Endocrinology Research, University of Western Australia.

“This involves making serial measurements of different parts of the body taken over time and plotting these measurements on a growth chart,” she said. “The most common parameters assessed are the weight, length or height and, in infants, their head circumference.”

As with adults, babies come in all shapes and sizes, and using more than one measurement is required to characterise the growth of a child.

“There’s significant normal variation in the population,” she said “Furthermore, different parts of the body grow at different rates and may be specifically affected by a chronic health condition.

“Therefore, a decrease or increase in weight is best assessed in relation to growth in length and head circumference. This provides a more complete and coherent assessment of a child’s health and wellbeing.”

In Australia, use of the World Health Organisation (WHO) growth charts for infants aged 0-2 years, and the US Centres for Disease Control (CDC) weight, height and BMI charts for monitoring growth in children and adolescents aged 2-18 years is recommended.

Growth charts, sometimes called percentile charts, consist of a series of percentile curves that illustrate the distribution of selected body measurements.

Ninety-four per cent of all babies and children grow within the centile range of the third to the 97th centiles, says Australian College of Midwives Principal Midwifery Officer Kellie Wilton.

“It’s a myth that health practitioners hope all babies are around the 50th centile,” she said. “It’s fact that approximately half the children at any age grow below the 50th centile, and half grow above the 50th centile.”

Serial weight and length/height measurements over time are needed for growth assessment, says Ms Wilton. Weight and length/height ‘tracking’ along centile lines shows healthy growth, while discrepancies can be a sign of issues that may have been missed at birth.

“It’s important to emphasise midwives as the primary care providers of pregnant women as they’re so invested in mothers’ health and are regularly tracking the growth of babies in the women’s antenatal notes prior to being born,” Ms Wilton said. “Following on, maternal child health nurses in the community are a service specialising in normal growth and welling being of children up to school age.”

Variations 

Very few children grow along the same centile line from birth

“Weight fluctuates and height don’t follow a linear path,” Ms Wilton said. “Babies and children have growth spurts irregularly, and of course, there can be genetic reasons, but also perhaps nutrition might not be optimal.”

Children around the world are being born into poverty, and environmental reasons such as poor drinking water and city smog can affect children’s physical health. In Australia, sociodemographic disadvantage is apparent, particularly in our remote indigenous communities, says Ms Wilton.

“Research shows us there’s a significant prevalence of undernutrition and obesity – both forms of malnutrition,” she said. “Healthcare providers, midwives and maternal child health teams need to align and provide tailored advice.”

Dr Choong says it’s important that interpretations of measurements are made in conjunction with a family history as there are specific familial patterns of growth.

“As with adults, babies and children vary in size relative to each other, due to a wide number of factors,” she said. “The factors that may impact are their gender, the timing of puberty, their genetics and birth history.”

The growth patterns of breastfed and formula-fed infants are also different.

“Healthy breastfed infants typically put on weight more slowly than formula-fed infants in the first year of life,” Dr Choong said.

“Formula-fed infants typically gain weight more quickly after about three months of age. Differences in weight patterns continue even after complementary foods are introduced.3

“If parents are concerned about an increase or decrease in the rate of their child’s growth, it is important that they speak to a healthcare professional who knows their child, like their local GP or paediatrician.”

Help and support

Ms Wilton says parents or carers should seek the advice of a health professional whenever their baby seems unwell or appears to not be gaining weight, “particularly in the first two years (or 1000 days) as we know this is when the basis for lifelong health, wellbeing and productivity is established,” she said.

Dr Choong says persistent low weight gain or movement across growth percentiles are signs that parents should seek healthcare professional advice.

“Likewise, if a baby loses developmental skills that they had previously, they should seek healthcare professional advice,” she said.

There are ways for parents to know if their baby is getting enough milk, such as pale urine, wet nappies, number of bowel movements and number of feeds.

“If this is appropriate but your baby is still not gaining weight, other factors, such as possible infection, reflux and even allergy to the foods the mother is eating, may be playing a part4,” Dr Choong said.

Pharmacy assistants can play an important role in supporting parents and helping them access appropriate information.

“Parents, particularly in the early days, can feel vulnerable, especially around feeding and growth,” Dr Choong said. “If they raise concerns, it’s important that you point them to evidence-based information, such as the fact sheet5 from the Royal Children’s Hospital in Melbourne and suggest that they talk to a healthcare professional who knows their child.

“Most parents will be linked with a GP, and parents can access early childhood nurses through their local council or local health district/network. You could find out the information for your local area and keep brochures or information to hand so that you can refer parents to easily accessible help.”

References

  1. who.int/tools/child-growth-standards/standards
  2. cdc.gov/growthcharts/index.htm
  3. cdc.gov/nccdphp/dnpao/growthcharts/who/breastfeeding/index.htm
  4. asn.au/bf-info/common-concerns%E2%80%93baby/baby-weight-gains
  5. org.au/childgrowth/about_child_growth/Top_10_things_you_need_to_know_about_growth_charts/

This feature was originally published in the April issue of Retail Pharmacy Assistants e-magazine.