Infection-Associated Preterm Birth: Advances From the Use of Animal Models

Worldwide, preterm birth (classically defined as delivery before 37 weeks' completed gestation) is a leading cause of neonatal death. Relative to their term-born peers, survivors of preterm birth are at increased risk of developing respiratory, neurological, and cognitive disorders, with the risk of death and disease being inversely proportional to gestational age at delivery. It is increasingly clear that preterm birth is a complex, multiorigin syndrome. Intrauterine infection is considered a leading cause of early preterm birth (delivery before 32 weeks' gestation); data from clinical and experimental studies suggest that infection accounts for upward of 40% of these high-risk preterm deliveries.This chapter is written with two aims: the first is to provide the reader with an introduction to infection-associated preterm birth, highlighting the importance of animal-based studies in advancing our understanding of this field; the second, adopting a more practical focus, is designed to provide the reader with technical insight into the use of pregnant sheep as a model organism for the study of fetal inflammatory responses to intrauterine infection and inflammation.