The study examined salivary immunoglobulin A (IgA) concentrations during pregnancy and at parturition. A significant drop in salivary IgA (p less than 0.001) occurred at parturition. State anxiety appeared to account for some of the variance in IgA concentration during pregnancy and at childbirth. Mothers who had very low or undetectable IgA concentrations when they gave birth had increased incidences of postpartum complications, and their infants had more illnesses during the first six weeks postpartum.