Women may present with psychiatric disorders during pregnancy, normal labor, following delivery by caesarean section, or in the postpartum period. The accumulating evidence suggests that these disorders may be due to changes in immune responses. During pregnancy complications such as the prolongation of cervical ripening or descent, placental abruption, premature labor, and preeclampsia increase the risk of postpartum psychiatric disorders. Women may exhibit depression and postpartum psychosis following either normal birth or caesarean section. Since psychiatric disorders like schizophrenia, major depression, and bipolar disorder are associated with both alterations in the immune response and changes in immune cell subpopulations, in this study we have chosen to examine whether the psychiatric disorders in women during labor or postpartum also lead to aberrant immune responses.