Maternal serum concentrations of insulin-like growth factor (IGF)-I and IGF binding protein-1 before and during pregnancy in relation to maternal body weight and composition and infant birth weight

Br J Nutr. 2010 Sep;104(6):842-8. doi: 10.1017/S0007114510001224. Epub 2010 May 11.

Abstract

Maternal nutritional status, e.g. body weight and composition, is associated with fetal growth. It has been suggested that the insulin-like growth factor (IGF) system may be a mediator of this relationship. In twenty-three healthy Swedish women, we studied (1) the relationships before and during pregnancy between maternal serum concentrations of IGF-I and IGF binding protein-1 (IGFBP-1) and maternal body weight and composition; (2) interactions between serum concentrations of IGF-I (before and in early pregnancy) and maternal nutritional status in relation to infant birth weight. We found that serum IGF-I during pregnancy was positively correlated with maternal body weight (r 0.47-0.56) and fat-free body weight (r 0.61-0.65), whereas serum IGFBP-1 was negatively correlated with maternal body weight (r - 0.44 to - 0.69) and body fat (r - 0.64 to - 0.76) before and during pregnancy. Women with a lower body fat content (%) before pregnancy had greater increases in serum IGFBP-1 during pregnancy than women with a higher prepregnant body fat content (%). In addition, significant fractions of the variation in corrected infant birth weight were explained by variables related to the maternal nutritional status when these were combined with serum concentrations of IGF-I in gestational week 14 (adjusted r2 0.25-0.44, P = 0.001-0.021), but not when they were combined with such concentrations before pregnancy (adjusted r2 0.11-0.12, P = 0.105-0.121). These results suggest mechanisms by which the IGF system may be a mediator between maternal nutritional status and fetal growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue
  • Birth Weight*
  • Body Composition*
  • Body Fluid Compartments
  • Body Weight*
  • Female
  • Fetal Development / physiology
  • Humans
  • Infant, Newborn*
  • Insulin-Like Growth Factor Binding Protein 1 / blood*
  • Insulin-Like Growth Factor I / metabolism*
  • Linear Models
  • Maternal Nutritional Physiological Phenomena
  • Nutritional Status
  • Pregnancy / blood*
  • Sweden

Substances

  • Insulin-Like Growth Factor Binding Protein 1
  • Insulin-Like Growth Factor I