Maternal and placental inflammatory biomarkers in spontaneous preterm delivery - Predictive ability, stability and neonatal associations
Year: 2017
Type: dissertation
Study design: Observational Study
Abstract: Preterm delivery (PTD), spontaneous or iatrogenic, causes short- and\nlong-term morbidity and underlies almost 75% of neonatal deaths. The prevalence in the Nordic countries is about 6% but it differs\namong countries. In the USA, for instance, it is around 9.6%.\nThe origin of spontaneous PTD is mostly unknown. However, infection\nand inflammation are leading causes, mainly at early gestational ages. Microbial invasion of the amniotic cavity (MIAC) occurs in 12-14% of\nsymptomatic women with preterm labor (PTL) and in 37-43% of\nwomen with preterm prelabor rupture of membranes (PPROM).\nMIAC elicits an inflammatory response mediated by cytokines,\nchemokines and other peptides, known as intra-amniotic inflammation\n(IAI). IAI causes early onset of symptoms, early gestational age at delivery and, consequently, worse neonatal outcome. Chemokines induce\nchemotaxis in neutrophils and macrophages, enhancing their migration to\nthe placenta and fetal membranes. This process, known as histological\nchorioamnionitis (HCA), occurs in more than half of spontaneous PTD\ncases. Early detection of spontaneous PTD presents a challenge because\nmost women who deliver preterm have no obvious risk factors that can be\nidentified early. Indeed, more than half of spontaneous PTDs occur in lowrisk pregnancies.\nOne aim of the studies in this thesis was to study whether non-invasive\nstrategies could predict the occurrence of spontaneous PTD within 7 days,\nas well as the rate of MIAC. We found that a combination of maternal\nserum proteins and cervical length constituted the most accurate prediction model for spontaneous PTD within 7 days of testing. However, we observed few differences between maternal serum protein levels in MIAC-positive PTL and PPROM cases.\nAn additional aim was to study the effect of different pre-analytical\nhandling procedures on concentrations of interleukin-6 (IL-6), the cytokine\nmost reported as a biomarker of IAI. We found that differences in handling\nprocedures did not affect amniotic fluid IL-6 levels.\nFurthermore, these studies investigated the relationship between neonatal\noutcome and placental histological findings in women with PPROM. We\nfound that HCA and funisitis increased the risk of early-onset neonatal\nsepsis and retinopathy of prematurity in PPROM pregnancies.
Author: Panagiotis Tsiartas
Language: English
Subfield: Obstetrics and Gynecology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2613529559