Cord serum insulin-like growth factor binding protein-1 and -3: effect of maternal diabetes and relationships to fetal growth.
OBJECTIVE
Insulin-like growth factor binding protein-1 and -3 (IGFBP-1 and -3) are the main insulin-like growth factor (IGF) carriers in fetal blood whose concentrations are regulated by hormonal factors such as insulin. IGFBPs may regulate fetal growth by altering the biological activity of IGF-I and IGF-II. We studied the effect of maternal diabetes on cord serum IGFBP-1 and IGFBP-3 levels, and the usability of IGFBP-1 and IGFBP-3 in the detection of birth weight variations.


METHODS
Cord serum IGFBP-1 and IGFBP-3 concentrations were measured at birth by immunofluorometric assays in 67 pregnancies with type 1 diabetes and in 62 normal pregnancies.


RESULTS
Concentrations of IGFBP-1 in cord serum were lower in diabetic pregnancies than in normal pregnancies (156 +/- 28 microg/l vs 266 +/- 29 microg/l, P = 0.007), whereas those of IGFBP-3 did not differ significantly (3327 +/- 158 microg/l vs 2982 +/- 105 microg/l, P = 0.076). IGFBP-1 correlated negatively and IGFBP-3 positively with birth weight z-score in diabetic pregnancies. The trend was similar in normal pregnancies. In multiple regression models, birth weight z-score was significantly associated with IGFBP-1 in diabetic and normal pregnancies, and with IGFBP-3 in diabetic pregnancies.


CONCLUSIONS
Maternal diabetes is associated with suppressed levels of IGFBP-1 in cord serum, whereas those of IGFBP-3 do not change markedly. In diabetic pregnancies, both cord serum IGFBP-1 and IGFBP-3 correlate with fetal growth.
Loukovaara
S
S
Department of Ophthalmology, Helsinki University Central Hospital, Helsinki, Finland. sirpa.loukovaara@hus.ti
Kaaja
R J
RJ
Koistinen
R A
RA
D000328:Adult; D015415:Biomarkers / Q000097:blood; D001724:Birth Weight; D015992:Body Mass Index; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D047109:Fetal Development; D006801:Humans; D007231:Infant, Newborn; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D010298:Parity; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000097:blood*; D012016:Reference Values
D015415:Biomarkers; D018970:Insulin-Like Growth Factor Binding Protein 1; D018972:Insulin-Like Growth Factor Binding Protein 3