DESCRIPTION (Adapted from applicant's description): Pregnancy is associated with substantial hormonal and anatomical changes primarily for the support and protection of the developing fetus. In fact, the leading cause of infant morbidity and mortality in the U.S. today, preterm birth, has been associated with upper genital tract infection which presumably ascends from the lower genital tract. However, no studies in the current literature have evaluated the mucosal immune system during pregnancy. In order to characterize mucosal immune factors of the lower genital tract in pregnancy, have propose the following specific aims: 1) To determine if there are longitudinal changes in the mucosal immune system of the lower genital tract (cervix and vagina) in pregnant women when followed in each trimester during pregnancy, 2) To determine if differences exist in mucosal immune factors of the lower genital tract in pregnant women at each trimester of pregnancy with and without selected risk factors (such as bacterial vaginosis, other pelvic infections, black race) for certain pregnancy complications.