Laminin in pregnancy.

Laminin, a noncollagenous glycoprotein component of basement membranes, was measured in human serum by radioimmunoassay for the laminin P1 fragment. The concentration of immunoreactive laminin increased during pregnancy. Before delivery it was nearly twice the level found in nonpregnant women. After delivery levels dropped. Decreased serum concentrations were detected in placental insufficiency whereas increased concentrations were found in sera of preeclamptic women. Immunoreactive serum laminin seems to correlate with the amount or degradation of placental basement membranes in pregnancy.