title: 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.
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.
authors.affiliation: Division of Nutrition, Department of Clinical and Experimental Medicine, Linköping University, SE-581 85 Linköping, Sweden. hanna.olausson@gu.se
authors.forename: Hanna
authors.initials: H
authors.lastname: Olausson
authors.forename: Marie
authors.initials: M
authors.lastname: Löf
authors.forename: Kerstin
authors.initials: K
authors.lastname: Brismar
authors.forename: Elisabet
authors.initials: E
authors.lastname: Forsum
authors.forename: Annica
authors.initials: A
authors.lastname: Sohlström
mesh_terms: D000273:Adipose Tissue; D001724:Birth Weight; D001823:Body Composition; D001825:Body Fluid Compartments; D001835:Body Weight; D005260:Female; D047109:Fetal Development / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D016014:Linear Models; D039382:Maternal Nutritional Physiological Phenomena; D009752:Nutritional Status; D011247:Pregnancy / Q000097:blood*; D013548:Sweden
chemical_list: D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I