Intrauterine infection, immune system and premature birth

Abstract

Preterm birth accounts for nearly one million deaths among children under five years of age, and although its etiopathogenesis is not fully elucidated, ascending intrauterine infection and fetal inflammatory response seem to be the main triggers. The intense inflammatory response mediated by IL-1β, TNF-α, PAF, IFN-γ and IL-6, PGE₂ and MMP-1 and MMP-9 causes fetal membrane damage and rupture, increased uterine contractions and biochemical and structural changes in the cervix. Furthermore, preterm neonates have deficient innate and adaptive immune responses characterized by reduced levels of IgG, opsonization and phagocytosis, as well as increased activation of Th1 cells in relation to Th2 cells. Therefore, this triad is favors the occurrence of neonatal complications, such as respiratory distress syndrome, necrotizing enterocolitis, retinopathy of prematurity and bronchopulmonary dysplasia. Due to serious maternal and child health complications of intrauterine infection, several studies have tried to identify biomarkers for the early diagnosis of this entity. This literature review aims to discuss the main scientific findings regarding the association between ascending intrauterine infection, immune system and preterm birth.

Keywords:

• Prematurity
• ascending intrauterine infection
• inflammation
• inflammatory response
• immune system

Acknowledgements

We thank Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Fundação de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG) and Fundação de Ensino e Pesquisa de Uberaba (FUNEPU) for financial support.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This study was funded by Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq) [grant number 470029/20110], Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) [grant number PNPD-02604/094], Fundação de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG) [grant number CDS-APQ-02135–14] and Fundação de Ensino e Pesquisa de Uberaba (FUNEPU) [grant number CDS-922/2009].