Periconceptual undernutrition resets plasma IGFBP levels and alters the response of IGFBP-1, IGFBP-3 and IGF-1 to subsequent maternal undernutrition in fetal sheep

Abstract

Maternal undernutrition inhibits fetal growth and alters circulating levels of insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs). This study investigates whether the fetal IGF axis could be reprogrammed by maternal undernutrition and hence be a potential contributing factor to changes in fetal and postnatal metabolism. Ewes were either fed ad lib. or undernourished from day −60 to day 30 of gestation, and then both groups were fed ad lib. These groups were further divided at day 105, either being fed ad lib or undernourished until day 115. Fetal blood samples were obtained at day 105 and day 115. IGFBP-1 and IGFBP-3 levels were lower at day 105 in the periconceptually undernourished fetuses. Levels of IGFBP-1 were increased and IGFBP-3, IGFBP-4, IGF-1, glucose and insulin were reduced at day 115 after undernutrition. The degree of change in IGFBP-1, IGFBP-3 and IGF-I between day 105 and day 115 was greater in fetuses receiving low periconceptual nutrition. These results indicate that periconceptual undernutrition is able to reprogramme the fetal IGF axis such that the responses of IGF-I and the IGFBPs to undernutrition in late gestation are markedly altered.