Postpartum maternal corticosterone decreases maternal and neonatal antibody levels and increases the susceptibility of newborn mice to herpes simplex virus-associated mortality.

The effects of corticosterone on the transmammary transfer of herpes simplex virus (HSV)-specific antibody and the ability of the neonate to survive HSV-2 infection were assessed. Increased postpartum maternal corticosterone reduced the levels of total and HSV-specific IgG in the serum and milk of mothers. Neonates nursed by these mothers received increased levels of corticosterone and decreased levels of total and HSV-specific IgG. Accordingly, these neonates were more susceptible to HSV-2-associated mortality; however, survival was restored through passive immunization with HSV-specific antibody. These studies demonstrate that postpartum elevations in corticosterone compromise a mother's ability to provide protective antibody to their offspring.