Differential expression and regional distribution of aquaporins in amnion of normal and gestational diabetic pregnancies.

The region of the amnion overlying the placenta plays an active role in fluid exchange between amniotic fluid and fetal blood perfusing the surface of the placenta, whereas little transfer occurs across the reflected amnion that contacts the membranous chorion. Because aquaporins (AQPs) facilitate rapid movement of water across cells, we hypothesized that AQP gene expression in placental amnion is higher than in reflected amnion. Furthermore, because gestational diabetes mellitus (GDM) is often associated with polyhydramnios, we hypothesized that amnion AQP gene expression is reduced when amniotic fluid volume is elevated.