Pulse wave velocity (PWV) is an indirect measure of vascular stiffness. Higher PWV is a recognised cardiovascular risk marker. Magnetic resonance imaging (MRI) is a non-invasive method of assessing PWV. Assessing maternal influences on offspring PWV is important as reduced fetal nutrient supply and impaired early development are linked with an increased risk of cardiovascular disease in adulthood. In multiparous women, changes in the uterine spiral arteries arising during previous pregnancies result in increased fetal nutrient supply. Rat studies have shown that changes in maternal fatty acid intake in pregnancy are associated with increased offspring arterial stiffness. Some studies of human adults suggest omega-3 fish oils reduce arterial stiffness. The objective of the study was to measure vascular stiffness using MRI, and examine maternal influences on vascular structure in children aged 9 years.