Medical Research: What are the main findings of the study?
Dr. Turner: There is evidence that being small for a given gestational age is associated with a broad range of what could be loosely considered “disadvantageous” outcomes in early childhood, eg increased risk for wheeze, increased blood fat levels, increased blood pressure and low bone mineral density. Many of these outcomes are subclinical – ie unless they were measured no-one would be any the wiser – and what remains to be determined is whether as these individuals grow up these subclinical measurements become important. Follow up may take many years, decades for outcomes such as coronary artery disease and type II diabetes.
Medical Research: Were any of the findings unexpected?
Dr. Turner: Yes, we had expected to find that fetuses who became smaller were at increased risk for “disadvantageous” outcomes but fetuses who grew fast were spared these. What we found was that both faltering and accelerated growth were associated with “disadvantageous” outcomes. This is consistent with the concepts of developmental plasticity and predictive adaptive responses where the fetus anticipates the environment in which it will be born and, rather like the weather forecast, it can be wrong. If the fetus is too big this might be bad in one environment but not another, similarly a fetus which is too small may not be able to make the most of a “good” environment. Ultimately, as identical twin studies have shown, a given individual is initially “plastic” and might or might not go on to develop a number of illnesses.
Medical Research: What should clinicians and patients take away from your report?
Dr. Turner: At this stage, nothing. Our conclusions are based on observations and it is possible that the same factor influencing fetal growth also leads to risk for disease and therefore manipulating fetal size may well not be helpful (and may paradoxically make risk for disease higher). This work gives some insight into the mechanisms leading/pre programming non-communicable diseases such as asthma, type II diabetes and hypertension. Mothers who are pregnant should continue to follow public health advice and eat and drink healthily, avoid cigarette smoke and exercise as much as they can.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Turner: The results are based on observations made in young children and we need to replicate these findings in older children and even adults. It seems highly likely that the antenatal and post natal environment are important in predicting future health and wellbeing (the first 1000 days following conception is probably very important) so it is important to link up growth in both the antenatal and postnatal periods to health and wellbeing.