First trimester maternal serum concentrations of fetal antigen 2 in normal pregnancies and those affected by trisomy 21.
Serum concentrations of fetal antigen 2 (FA-2), the amino-propeptide of the alpha1 chain of collagen type I, were measured in peripheral blood from women with normal (n = 234) and trisomy 21 affected (n = 14) pregnancies between 9 and 11 weeks gestation. Serum FA-2 concentrations were seen to be stable throughout this period, and though raised FA-2 concentrations were seen at the 10th week of gestation, a statistically significant difference between normal and trisomy 21 affected pregnancies was not found overall. Therefore it seems unlikely that FA-2 has a role in first trimester screening for trisomy 21, despite the fact that significantly higher FA-2 concentrations in trisomy 21 and significantly lower concentrations in trisomy 18 had been previously demonstrated in amniotic fluid in the second trimester.
Department of Obstetrics and Gynaecology, St Bartholomew's & the Royal London School of Medicine and Dentistry, Queen Mary & Westfield College, UK.
K M
KM
Price
J M
JM
Van Lith
R
R
Silman
A
A
Mantingh
J G
JG
Grudzinskas
D001681:Biological Assay; D024042:Collagen Type I; D004314:Down Syndrome / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D005260:Female; D005326:Fetal Proteins / Q000032:analysis*; D005819:Genetic Markers; D006801:Humans; D008403:Mass Screening; D010446:Peptide Fragments; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D011261:Pregnancy Trimester, First / Q000097:blood* / Q000276:immunology; D011347:Procollagen
D024042:Collagen Type I; D005326:Fetal Proteins; D005819:Genetic Markers; D010446:Peptide Fragments; D011347:Procollagen; C047202:procollagen Type I N-terminal peptide