The fetal origins of disease hypothesis contends that an unfavourable intrauterine environment, as evidenced by low birth weight, increases vulnerability to chronic illness in adulthood.¹ There is now reasonably consistent evidence of a negative association between birth weight and adult blood pressure.² However, the mechanisms underlying this relation remain unclear. It has been suggested that individual differences in susceptibility to stress may play a part.³ One way of assessing this susceptibility is by measuring blood pressure reactions to an acute psychological stress task. There is evidence that large magnitude blood pressure reactions to such exposures predict increased resting blood pressure at subsequent follow up.⁴ Our analyses revisited the issue of birth weight and adult blood pressure and examined …