Richardson Bryan S, Wakim Emma, daSilva Orlando, Walton John
Department of Obstetrics and Gynaecology, St. Joseph's Health Care, University of Western Ontario, London, Ontario, Canada.
Am J Obstet Gynecol. 2006 Nov;195(5):1357-65. doi: 10.1016/j.ajog.2006.03.053. Epub 2006 May 3.
The purpose of this study was to further delineate the impact of preterm chorioamnionitis on a spectrum of neonatal outcomes using a large tertiary hospital population.
The perinatal/neonatal and placental pathology databases of St. Joseph's Health Care, London, Ontario, Canada, were used to obtain the umbilical cord gas and pH values, incidence of adverse neonatal outcomes, patient demographics, and placental pathology reports for all preterm (25 to 34 weeks of gestation), singleton, liveborn infants with no major anomalies who were delivered with spontaneous onset of labor or for suspected chorioamnionitis between November 1, 1995, and October 31, 2003. Patient groupings on the basis of placental inflammation and clinical chorioamnionitis were studied by a comparison of mean values and incidences for those neonatal outcomes that were available from the database with the use of linear and logistic regression analysis and controlling for potentially confounding variables.
There were 660 infants who met the inclusion criteria and had placental pathology available of whom 368 (56%) had no placental inflammation, 114 (17%) had placental chorioamnionitis, and 178 (27%) had placental funisitis. Umbilical cord partial pressure oxygen and base excess values were generally higher in the placental inflammation/clinical chorioamnionitis groups, in keeping with enhanced oxygen delivery and an overall decrease in the metabolic contribution to acidosis attributed to altered lactate metabolism in these infants. After adjusting for confounders (primarily differences in gestational age), the incidence of respiratory distress syndrome was significantly decreased in the placental inflammation/clinical chorioamnionitis groups, in keeping with cytokine-induced synthesis of surfactant proteins in these infants. Although the incidence of bronchopulmonary dysplasia, intraventricular hemorrhage, and periventricular leukomalacia was generally unchanged among the groups studied, that for intraventricular hemorrhage and periventricular leukomalacia was lowest in the placental inflammation/no clinical chorioamnionitis patients and highest in the placental inflammation/clinical chorioamnionitis patients, suggesting a differential effect of clinical chorioamnionitis for these outcomes.
Overall, infants born preterm with intrauterine infection were better oxygenated and showed less metabolic acidosis at birth and had incidences of respiratory distress syndrome and intraventricular hemorrhage, which were variably lower. Although there are likely threshold levels of inflammatory cytokines that do give rise to adverse outcome, a minimal level of cytokines may also be beneficial for the transition at birth from intrauterine to extrauterine existence when preterm pending the circumstances (ie, exposure to antenatal steroids) and emphasizing the complex relationship among preterm birth, infection, and adverse neonatal outcome.
本研究旨在利用一家大型三级医院的人群，进一步阐明早产绒毛膜羊膜炎对一系列新生儿结局的影响。
利用加拿大安大略省伦敦市圣约瑟夫医疗保健中心的围产期/新生儿及胎盘病理学数据库，获取所有孕周为25至34周、单胎、无重大畸形、自然发动分娩或1995年11月1日至2003年10月31日期间因疑似绒毛膜羊膜炎而分娩的活产婴儿的脐带血气和pH值、不良新生儿结局发生率、患者人口统计学资料以及胎盘病理学报告。通过比较数据库中可获得的那些新生儿结局的平均值和发生率，并使用线性和逻辑回归分析以及控制潜在的混杂变量，对基于胎盘炎症和临床绒毛膜羊膜炎的患者分组进行研究。
有660名婴儿符合纳入标准并可获得胎盘病理学资料，其中368名（56%）无胎盘炎症，114名（17%）有胎盘绒毛膜羊膜炎，178名（27%）有胎盘脐带炎。胎盘炎症/临床绒毛膜羊膜炎组的脐带血氧分压和碱剩余值通常较高，这与这些婴儿氧输送增加以及由于乳酸代谢改变导致酸中毒的代谢贡献总体降低一致。在对混杂因素（主要是孕周差异）进行调整后，胎盘炎症/临床绒毛膜羊膜炎组的呼吸窘迫综合征发生率显著降低，这与这些婴儿中细胞因子诱导的表面活性物质蛋白合成一致。虽然在所研究的组中支气管肺发育不良、脑室内出血和脑室周围白质软化的发生率总体上没有变化，但脑室内出血和脑室周围白质软化的发生率在胎盘炎症/无临床绒毛膜羊膜炎患者中最低，在胎盘炎症/临床绒毛膜羊膜炎患者中最高，这表明临床绒毛膜羊膜炎对这些结局有不同的影响。
总体而言，早产并伴有宫内感染的婴儿出生时氧合较好，代谢性酸中毒较轻，呼吸窘迫综合征和脑室内出血的发生率也有所降低。虽然可能存在确实会导致不良结局的炎性细胞因子阈值水平，但当早产时，在某些情况下（即暴露于产前类固醇），最低水平的细胞因子可能也有利于从宫内到宫外的过渡，这强调了早产、感染和不良新生儿结局之间的复杂关系。
