Infant arterial stiffness and maternal iron status in pregnancy: A UK birth cohort (Baby VIP study)

Background In animal studies, iron deficiency during pregnancy has been linked to increased offspring cardiovascular risk. No previous population studies have measured arterial stiffness early in life to examine its association with maternal iron status. Objective This study aimed to examine the association between maternal iron status in early pregnancy with infant brachio-femoral pulse wave velocity (PWV). Methods The Baby VIP (Baby’s Vascular health and Iron in Pregnancy) study is a UK-based birth cohort which recruited 362 women after delivery from the Leeds Teaching Hospitals postnatal wards. Ferritin and transferrin receptor levels were measured in maternal serum samples previously obtained in the first trimester. Infant brachio-femoral PWV was measured during a home visit at 2-6 weeks. Results Iron depletion (ferritin <15 ug/L) was detected in 79 (23%) women in early pregnancy. Infant PWV (m=6.7 m/s, sd=1.3, n=284) was not associated with maternal ferritin (adjusted change per 10 ug/L= 0.02, 95% CI -0.01, 0.1), nor with iron depletion (adjusted change = -0.2, 95% CI -0.6, 0.2). No evidence of association was observed between maternal serum transferrin receptor level or its ratio to ferritin with infant PWV. Maternal anaemia (<11 g/dL) at ≤20 weeks gestation was associated with a 1.0 m/s increase in infant PWV (adjusted 95% CI 0.1, 1.9). Conclusion This is the largest study to-date which assessed peripheral PWV as a measure of arterial stiffness in infants. There was no evidence of an association between markers of maternal iron status early in pregnancy and infant PWV.