A perinatal pathology view of preterm labor.

The development and widespread use of tocolytic agents over the past 2 decades has not appeared to substantially affect the overall incidence of preterm delivery in the United States. Preterm delivery, therefore, remains one of the most poorly controlled and poorly understood mechanisms of perinatal morbidity and mortality and a significant strain on public health resources. The purpose of this review is to examine what is currently understood about the clinical manifestations and indicators of preterm delivery, and what, if any, may be the contribution of placental pathology to the understanding of the structural and functional abnormalities that may precede these clinical signs. Two case studies will be used to show how placental pathology may document a pattern of reproductive failure that eludes current methods of clinical screening. A retrospective analysis of what may have gone wrong in the pregnancies, focusing on the placental lesions, may contribute to a greater understanding of the heterogeneous overall processes behind recurrent idiopathic preterm delivery. Such analysis, in conjunction with known clinical factors, may guide the development of better-directed diagnostics and therapies.