Abstract: Toll like receptors （TLRs） have been identified as transmembrane signal transduction proteins in
recent years. As a group of pattern recognition receptors （PRRs）, TLRs are important regulators of the innate immune
response based on their ability to recognize and respond to pathogen-associated molecular patterns expressed by
microbes. Genetic polymorphisms affect the susceptibility of individuals and single nucleotide polymorphisms of TLR
genes, which are associated with the inflammatory responses and susceptibility to infectious diseases. With the development of
reproductive immunology, relevant studies of TLRs and their gene polymorphism and preterm birth have been gradually carried
out, providing new concepts and ideas for diagnosis, treatment and prognosis of premature cases.

Key words: Toll like receptors, Genetic polymorphisms, Preterm birth, Immune, Placenta