Monitoring exclusive maternal breastfeeding using nuclear techniques

In countries where the infant mortality rate for children under one year of age is high, any action that can be taken can make a significant difference. This is the case, according to the World Health Organization, children exclusively breastfed for the first six months of life are more resistant to disease and infection than those fed infant formula.

Therefore, with this in mind, great efforts were made to carry out information campaigns in countries such as South Africa where there was a high risk of malnutrition, disease, and even death of infants. However, the results were not as expected and, although the mortality rate was reduced, the decrease was not proportional.

Health professionals realised that they had started from the information on breastfeeding frequency provided by the mothers, however, they did not know the exact figures on how many babies were being exclusively breastfed and when complementary foods were being introduced into the babies' diets. This situation became a problem in making decisions and looking for the most appropriate measures.

In this regard, a non-radioactive nuclear method called the ‘deuterium dilution technique’ could provide these figures. It involves the mother drinking water labelled with deuterium, a stable, non-radioactive isotope of hydrogen. It mixes with the water in the mother's body, including her milk, and enters the baby when the baby suckles. The mother's saliva and the baby's saliva become deuterium-containing. Scientists regularly take saliva samples over the next two weeks and measure the deuterium content. The amount found is directly proportional to the amount of breast milk the baby has ingested, and the technique also indicates whether the baby has ingested anything other than human milk during the testing period.

How is the amount of deuterium known? A mathematical model determines the amount of deuterium supplied to the mother that appears in the baby's saliva, and this proportion depends on the amount of human milk the baby has consumed. The model also makes it possible to estimate the amount of water from sources other than breast milk and whether or not the baby has been exclusively breastfed.

Based on these, programmes such as long-term mentoring of new mothers, who were simultaneously trained as breastfeeding counsellors, and the deuterium dilution technique would be used to validate mothers' reported breastfeeding practices.