The research, published today in Public Library of Science: Medicine, is the first study to demonstrate a link between a single technological development intervention (in this case, a tapped water supply) and an increase in both birth rate and childhood malnutrition.
Dr Mhairi Gibson of Bristol University's Department of Archaeology and Anthropology and Dr Ruth Mace of University College, London examined nearly 2,000 households in rural Ethiopia over a four year period during which a tapped water supply was introduced but family planning provisions were absent. They looked at the nutritional status of women and children (in terms of weight and height) and birth rates in villages where tapped water had been introduced and others where it had not.
While previously, women had to walk up to 30 km to fetch their families' water, the new water supply reduced the time spent carrying water each day from around three hours to about 15 minutes. The availability of tapped water improved the survival of young children and the birth rate increased. However, the nutritional status of young children declined.
Overall, neither women's health nor nutritional status appeared to be improved by the reduced workload, lending support to the idea that the energy women save due to new development technology is being diverted towards reproduction, resulting in greater fertility and reduced mortality. However, since food and other resources are already scarce, this comes at the cost of an increase in childhood malnutrition.
Dr Gibson said: "This study is, to our knowledge, the first to demonstrate a link between a technological development intervention and an increase in both birth rate and childhood malnutrition. Women's nutritional status was not improved by the energy-saving technology, because energy was diverted into higher birth rates.
"This research shows that development projects that focus on just one issue can cause long-term problems and that it is preferable for development to be 'multisectoral'. Improving access to contraception, which was poor in the area where this study was done, should be a key part of development programmes."