The relationship among circulating insulin-like growth factor (IGF)-I, IGF-binding proteins-1 and -2, and birth anthropometry: a prospective study.
Fetal IGF-I is a determinant of birth weight, but whether maternal IGF-I plays a significant role is controversial. We sought to examine the relationships among maternal IGF-I, IGF-binding protein (IGFBP)-1, and IGFBP-2, with maternal and newborn anthropometry, in a cohort of 325 nondiabetic pregnant women of African origin. Blood was collected for IGF-I, IGFBP-1, and IGFBP-2 at 9, 25, and 35 wk gestation and in cord blood at delivery. In the second and third trimesters, maternal IGF-I was significantly correlated (P < 0.005) with maternal body mass index and triceps skinfold thickness. Maternal IGFBP-1 and -2 had an inverse correlation (P < 0.0001), with maternal anthropometry. Maternal IGF-I at 35 wk, and fetal IGF-I by cord blood were significantly correlated with birth weight (P = 0.001 and 0.048, respectively). IGFBP-1 in the third trimester and cord blood were negatively correlated with birth weight (P = 0.012 and 0.002). In multiple regression analyses, maternal IGF-I at 35 wk, fetal IGF-I, maternal weight at the first antenatal visit, gender, and gestational age were significant independent factors in the determination of birth weight. In conclusion, maternal IGF-I levels, especially during late pregnancy, positively influence birth weight.
Boyne
Michael S
MS
Tropical Metabolism Research Unit, Tropical Medicine Research Institute, The University of the West Indies, Mona, Kingston 7, Jamaica.
Thame
Minerva
M
Bennett
Franklyn I
FI
Osmond
Clive
C
Miell
John P
JP
Forrester
Terrence E
TE
D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D009752:Nutritional Status; D011247:Pregnancy; D011446:Prospective Studies; D012044:Regression Analysis; D012885:Skinfold Thickness
D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D007334:Insulin-Like Growth Factor I