Improved lymphocyte ectoenzyme function during normal pregnancy.

During normal pregnancy, the 5'-nucleotidase (AMPase) enzyme activity on the circulating human lymphocyte pellet has been found to be increased significantly (p less than 0.001) in comparison with that of healthy normal persons employed as controls. The increased lymphocyte activity diminished rapidly subsequent to parturition. The enzyme activity on lymphocytes purified from umbilical cord blood was not increased. Acute viral infections induced a transient reduction in the enzyme activity. Further studies of this natural defence mechanism are in progress.