Aj. Kelly et al., LOW-LEVELS OF AMNIOTIC-FLUID PREGNANCY-SPECIFIC BETA-1-GLYCOPROTEIN IN DOWNS-SYNDROME, Early human development, 37(3), 1994, pp. 175-178
Amniotic fluid levels of beta-1-glycoprotein (SP1) were measured in 46
cases of Down's syndrome and compared with levels in 106 pregnancies
of normal karyotype from 10 to 23 weeks of gestation. In normal pregna
ncies, levels rose from 87.5 iu/l at 10 weeks to a peak of 610.0 iu/l
at 19 weeks of gestation. In cases of Down's syndrome, levels were red
uced prior to 19 weeks of gestation (median multiple of the median, Mo
M = 0.75, P = 0.02). This effect was most marked prior to 16 weeks of
gestation when the median multiple of the median (MoM) was 0.51 (P = 0
.006). These data demonstrate that amniotic fluid levels of SP1 are lo
w in Down's syndrome before 19 weeks of gestation.