Background: Cardiovascular disease may have its origins in utero, but the influence of in utero growth on microvascular structure in children is unknown. We hypothesized that poor in utero growth is associated with narrower arteriolar caliber, which may help explain the established association of low birth weight with hypertension and cardiovascular disease in adulthood.
Methods and results: We examined the relation of birth weight and other markers of in utero growth to microvascular caliber in the retina in a population-based study of 1369 6-year-old children in Sydney, Australia (Sydney Childhood Eye Study). Birth weight, birth length, and head circumference were obtained from parental records. Retinal arteriolar and venular calibers were measured from digitized retinal photographs by a validated computer-assisted method. Lower birth weight, shorter birth length, and smaller head circumference were associated with narrower retinal arteriolar caliber. Each kilogram decrease in birth weight was associated with a 2.3-mum (95% CI 0.6 to 3.9, P=0.01) narrower retinal arteriolar caliber after controlling for age, gender, ethnicity, height, body mass index, axial length, mean arterial blood pressure, and prematurity. Similar associations were observed between shorter birth length and smaller head circumference with narrower retinal arteriolar caliber.
Conclusions: Children who had lower birth weight, shorter birth length, and smaller head circumference had narrower retinal arteriolar calibers. These data support the concept that poor in utero growth may have an adverse influence on microvascular structure.