Dec 14, 2007

Small and Thin

There was an article in the New Yorker (Nov 19, 2007) that had some disturbing news. For almost 20 years, scientists have been debating the "Barker Hypothesis" which found a strong association between low birthweight and increased risk of adult diseases like coronary heart failure, hypertension, type 2 diabetes, and strokes. Although initially dismissed as heretical, these findings have been repeatedly confirmed in recent epidemiological studies. The causal mechanism behind this finding appears to be a complex dialogue between fetus and mother's body---in which the fetus or even embryo adapts itself to the nutrient levels in the maternal environment. In cases where the nutrient levels are less than ideal, the fetus adapts by slowing its growth and thereby lowering its ultimate birthweight. Ironically, such infants later find the more plentiful nutrition of the postnatal environment a stressor rather than an aid to growth. Most at a disadvantage are those children who are born with low birthweight, but gain rapidly in BMI after two years of age.

This last conclusion has serious implications for parents of low birthweight babies (two thirds of whom are premature in the US). If it is dangerous for premature babies to grow too big, too fast, after age two, shouldn't we be more interested in these kids maintaining their percentile position rather than trying to jump up into higher percentiles. Are pediatricians aware of these studies and advocating against rapid weight gains between 2-5 years of age?

What does your pediatrician say? Please let us know...