High expression of α1,2- AND α1,6-linked fucoses on amniotic AGP as a biomarker of fetal postmaturity risk.

We aimed to analyze possible alternations in the sialylation and fucosylation of α(1)-acid glycoprotein (AGP) in pregnancies complicated by postmature syndrome. The relative amounts of sialyl- and fucosyl-glycotopes on AGP were analyzed in 49 plasma and 49 amniotic fluid samples from postmature and normal pregnancies with gestational ages of 41 to 42 weeks by lectin-ELISA using sialic acid- and fucose-specific biotinylated lectins. The amniotic AGP derived from pregnancies complicated by fetal postmaturity contained higher relative amounts of the exposed innermost α1,6- (p < 0.04) as well as outer α1,2-linked fucoses (p < 0.01) compared with normal pregnancies. These changes were limited to the fucosylation, not sialylation, of amniotic AGP, and did not appear in maternal plasma AGP. The over-fucosylation of amniotic AGP may be considered a biochemical marker to monitor pregnancies and predict postmature syndrome complications in newborns, especially in pregnancies ending after 41 weeks.