Monitoring infant weight helps us assess their health and nutritional status. When concerns with health or nutrition are identified early, outcomes are often better. This is why infant weight gain is so closely monitored over the first years of life.
Indicators for weight monitoring in infancy?
The reason for monitoring infant weight comes from the general understanding that improved nutritional status leads to improved health of total populations. For this reason, it has become an integral part of most primary health care systems.
A review on the evidence discussed the various levels of reported benefits associated with growth monitoring. The author of this review stated that at the time of writing (2007) there was a lack of quality studies on the benefit of growth monitoring. However, they also wrote that it can ‘provide an entry point to preventative and curative health’ and that it is ‘associated with significant reductions in malnutrition and mortality’.
Introduction to WHO growth charts
Growth monitoring originated in the mid 1800’s, with the purpose of assessing breastfeeding in young babies. Subsequently, health professionals began weighing infants and references for growth were developed. Growth charts were first recommended by a committee within the WHO in the 1960’s, who later published a standardised chart along with guidelines for use.
Growth charts used in Ireland and the UK
In Ireland and the UK, the same growth charts are used today (UK-WHO charts). These were created by the Royal College of Paediatrics and Child Health, based on data from the WHO growth references as well as data from the previously used UK charts (UK90 data).
The WHO growth references encompass data from a large multicentre study that included healthy, breastfed infants from various countries, including Oman, India, Norway and Brazil. The UK90 data was collected in 1990 from seven different sources across the UK, a very high proportion of the infants included in this dataset were white.
Use of these charts in the UK was recommended in 2009 by the Scientific Advisory Committee on Nutrition. In 2010, the Irish Department of Health and Children decided to adopt the same charts for use within Ireland.
The UK-WHO charts have 4 different charts for tracking weight; 0-4 years, 4-12 years, charts for down’s syndrome and charts for very pre-term infants or those with significant health problems. Different charts are used for girls and boys. On these charts there are centiles, illustrated by curved lines.
What are weight centiles and why do they matter?
Centiles (or percentiles) are used to depict the distribution of infant weights at each age. Each centile represents 10% of the overall data set. For example, if a baby falls within the 40th centile, this means their weight is 60% lower than the highest data point, but 40% higher than the lowest. Weight centiles essentially allow us to compare the weight of an infant with their peers of the same sex and age.
As mentioned previously, monitoring infant growth can provide insight into the health and nutritional status of babies. We do it so that issues can be identified and troubleshooted accordingly. There are certain guidelines which health professionals must follow if they find that a baby is experiencing ‘faltering growth’. Usually this involves more frequent growth measurements and enhanced support with infant feeding and care.
Full picture view
The full picture view of a baby’s health should always be considered in addition to weight measurements. When growth monitoring shows a downward or plateaued trend in baby’s weight, more information on their general well-being and nutrition is required.
The interpretation of the full picture can be subjective. Although there are some important signs you can monitor yourself to help contextualise your baby’s weight measurements.
Signs that baby is healthy and nutritionally fulfilled include:
- Sufficient wet and dirty nappies. Over 6 days of age babies should have at least 6 wet nappies per day. Dirty nappies can be more variable, and most babies will develop their own normal pattern, but on average should be 2-3 per 24 hours.
- Contented after feeds. Babies who are getting enough milk will generally come off the breast themselves and be contented and satiated, with periods of sleepiness. When a baby is very alert / upset and seeking fed consistently, this may indicate a problem with feeding.
Check out our post on understanding low milk supply to read more on the signs that baby is getting enough milk.
If you have any concerns about your babies growth or feeding, reach out to your GP or public health nurse / midwife. It is important to seek professional help as early as possible if you notice anything concerning. They will be able to assess babies health and nutrition, including their weight, and signpost you to further support if needed.
References
Ashworth, A., Shrimpton, R., & Jamil, K. (2008). Growth monitoring and promotion: review of evidence of impact. Matern Child Nutr, 4 Suppl 1(Suppl 1), 86-117. https://doi.org/10.1111/j.1740-8709.2007.00125.x
Cole, T. J., Wright, C. M., & Williams, A. F. (2012). Designing the new UK-WHO growth charts to enhance assessment of growth around birth. Arch Dis Child Fetal Neonatal Ed, 97(3), F219-222. https://doi.org/10.1136/adc.2010.205864
Espejo, M. R. (2007). WHO Child Growth Standards: Methods and Development. Journal of the Royal Statistical Society Series A: Statistics in Society, 170(2), 512-512. https://doi.org/10.1111/j.1467-985X.2007.00473_18.x
Freeman, J. V., Cole, T. J., Chinn, S., Jones, P. R., White, E. M., & Preece, M. A. (1995). Cross sectional stature and weight reference curves for the UK, 1990. Arch Dis Child, 73(1), 17-24. https://doi.org/10.1136/adc.73.1.17
WHO. (2006). WHO Child Growth Standards based on length/height, weight and age. Acta Paediatr Suppl, 450, 76-85. https://doi.org/10.1111/j.1651-2227.2006.tb02378.x