Infection-Related Preterm Birth

Preterm birth (PTB), predominantly induced by intraamniotic inflammation, stands as the foremost contributor to neonatal morbidity and mortality globally. Fetal inflammatory response syndrome, stemming from the activation of the innate immune system, signifies the occurrence of funisitis or chorionic vasculitis. Maternal-fetal complications associated with infection-related PTB encompass maternal sepsis, fetal demise, neonatal sepsis, neonatal neurological impairment, and chronic lung disease. The inflammatory cascade is initiated when Toll-like receptors present on immune cells within the fetal membranes and the female reproductive tract encounter pathogen-associated molecular patterns derived from infectious agents. Subsequently, the nuclear factor kappa-light-chain-enhancer of activated B cells facilitates the transcription of cytokines. The accumulation of neutrophils compromises the tissue integrity of the fetal membranes, leading to membrane rupture via the secretion of matrix metalloproteinases. Elevated prostaglandin levels prompt uterine contractions and cervical remodeling, resulting in progressive cervical effacement and dilation, ultimately culminating in fetal delivery. The diagnosis of PTB should encompass three pivotal criteria: gestational age, uterine activity, and the consequences of that uterine activity. The diagnosis of chorioamnionitis is established through a combination of clinical manifestations, laboratory findings, identification of infectious microorganisms, and placental pathology. Fetal monitoring involves antenatal ultrasonography and non-stress testing. The management of infection-related PTB involves controlling and treating the infection, timing delivery to coincide with optimal fetal lung maturity, and optimizing outcomes for both the mother and neonate. Current preventive strategies for PTB primarily focus on inhibiting myometrial contractions that arise from the inflammatory cascade initiating PTB. An understanding of these pathways serves as the cornerstone for the development of therapeutic interventions aimed at preventing PTB.