Association of malaria in pregnancy with maternal metabolic biomarkers, cord blood IGF-I and birth size in Nigerian infants: The Ibadan Growth and Vascular Health Study
O O Ayoola1,2, A J Whatmore1,2, J K Cruickshank1,2 & P E Clayton1,2
Malaria is commoner amongst pregnant than non-pregnant women in Nigeria and is associated with a significant risk of having a low birth weight (LBW) baby which increases later risk of disease, in particular hypertensive heart disease in this population.
We have established a birth cohort in Nigeria and in this study; we aimed to identify possible biomarkers in maternal and/or cord blood related to birth size on the background of malarial status in pregnancy.
During pregnancy, anthropometric measurements, blood film for malaria parasites and assays for lipids, glucose, insulin and TNFα were obtained from 410 mothers and these analytes and IGF-I were obtained from 187 babies at birth. Data were analysed by non-parametric tests.
Prevalence of malaria parasitaemia in pregnancy was 48% associated with younger age, anaemia and thinner, shorter babies with smaller occipitofrontal circumference (OFC) and mid upper arm circumference (MUAC). There was no effect of maternal malaria on cord blood lipids, glucose, insulin and TNFα but median (range) cord IGF-I was significantly lower in babies whose mothers had malaria compared with those without malaria [60.4 (24,145) vs 76.5 (24, 150) ng/ml] (P=0.03).
Maternal glucose (r2=0.17, P=0.03), insulin (r2=0.19, P=0.012), cord blood insulin (r2=0.18, P=0.017) and IGF-I (r2=0.17, P=0.025) were all positively associated with birth weight. MUAC correlated positively with maternal cholesterol, LDL and cord IGF-I while OFC correlated with maternal glucose. On regression analysis, cord glucose (β=0.04, P=0.025) but more significantly IGF-I (β=0.003, P=0.005) were independently associated with birth weight.
Malaria in pregnancy was common and associated with LBW and lower IGF-I levels. Cord blood glucose and IGF-I but not maternal metabolic markers were significant determinants of birthweight. Follow up through infancy will determine whether poor growth and low IGF-I in those with maternal malaria is a persistent feature.