title: Levels of insulin-like growth factor-binding protein-1 increase rapidly in amniotic fluid from 11 to 16 weeks of pregnancy.
abstract: Concentrations of IGF-binding protein-1 (IGFBP-1) were measured by radioimmunoassay in 176 amniotic fluid samples from 9 to 20 and 36 to 42 weeks of pregnancy. Low levels of IGFBP-1 were present at 9 and 10 weeks (median values 35.0 and 45.0 micrograms/l respectively). After 10 weeks, the levels increased by four orders of magnitude to reach a peak at 16 weeks (median 145.2 mg/l). After 16 weeks levels fell. Near term, the levels (median 27.1 mg/l) were lower than in the second trimester. The rapid increase in IGFBP-1 shown by radioimmunoassay was confirmed by Western ligand blotting. The findings suggest that the regulatory role of IGFBP-1 in the growth or differentiation of the fetus or of its surrounding membranes may change as pregnancy advances.
authors.affiliation: Combined Academic Department of Obstetrics, Gynaecology, St Bartholomew's Hospital, West Smithfield, London, UK.
authors.forename: N C
authors.initials: NC
authors.lastname: Wathen
authors.forename: S
authors.initials: S
authors.lastname: Egembah
authors.forename: D J
authors.initials: DJ
authors.lastname: Campbell
authors.forename: A
authors.initials: A
authors.lastname: Farkas
authors.forename: T
authors.initials: T
authors.lastname: Chard
mesh_terms: D000653:Amniotic Fluid / Q000378:metabolism*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1; D011247:Pregnancy / Q000378:metabolism*; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011863:Radioimmunoassay; D013002:Somatomedins / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D013002:Somatomedins