Both biological and behavioral changes have been hypothesized
to explain the potentially higher risk of HIV acquisition observed
during pregnancy and the postpartum period. Behavioral factors were not associated with HIV acquisition in two prior studies of
pregnant and postpartum women [3,6]; however, behavior
changes in male partners during the pregnancy/postpartum
period have not been well characterized and could play a role in
maternal HIV risk, particularly if partners increase sexual activity
outside of the relationship. Pregnancy-induced physiological
changes have been hypothesized to increase HIV susceptibility,
through changes in systemic and mucosal immunity, disturbances
in vaginal flora, and alterations of the genital mucosa.