Microbiota y perfil inmunológico vaginal de la embarazada propensa a parto prematuro por infección bacteriana ascendente. Revisión narrativa

Preterm delivery (PD) is the leading cause of perinatal morbidity/mortality in the world. Intrauterine infection is the most frequent origin of spontaneous PD (SPD) in a public hospital in Chile.There is evidence that vaginal ascending bacterial infection (ABI) causes intra-amniotic infection/inflammation, SPD, and adverse maternal and perinatal outcomes.This narrative review includes systematic reviews and cohort or case-control studies on the microbiota and immunological profile existing in the lower genital tract (LGT) of pregnant women prone to SPD due to ABI. There is consensus that in the LGT microbiota of this pregnant woman there is vaginal colonization with low abundance of Lactobacilli and/or decreased quality, due to racial and/or geographic, or genetic differences and dysregulation of immunological mechanisms of the LGT. These responses occur with greater intensity in patients with host risk factors, such as diabetes, obesity, stress, anxiety, and depression, causing recurrent LGT infections responsible for SPD and perinatal outcomes. Knowledge of the behavior of the microbiota and the immune system in these cases will allow effective therapies to prevent SPD and neonatal morbidity/mortality due to ABI.