Locksmith G, Duff P
Division of Maternal-Fetal Medicine, University of Texas Medical Branch--Galveston, 77555-0587, USA.
Semin Perinatol. 2001 Oct;25(5):295-309. doi: 10.1053/sper.2001.27163.
The relationship between genital tract infection and preterm delivery has been established on the basis of biochemical, microbiological, and clinical evidence. In theory, pathogenic bacteria may ascend from the lower reproductive tract into the uterus, and the resulting inflammation leads to preterm labor, rupture of the membranes, and birth. A growing body of evidence suggests that preterm labor and/rupture of the membranes are triggered by micro-organisms in the genital tract and by the host response to these organisms, ie, elaboration of cytokines and proteolytic enzymes. Epidemiologic and in vitro studies do not prove a cause-and-effect relationship between infection and preterm birth. However, the preponderance of evidence indicates that treatment of asymptomatic bacteriuria and symptomatic lower genital tract infections such as bacterial vaginosis (BV), trichomoniasis, gonorrhea, and chlamydia will lower the risk of preterm delivery. Based on current evidence, pregnant women who note an abnormal vaginal discharge should be tested for BV, trichomonas, gonorrhea, and chlamydia. Those who test positive should be treated appropriately. A 3- to 7-day course of antibiotic treatment for asymptomatic bacteriuria during pregnancy is clinically indicated to reduce the risk of pyelonephritis and preterm delivery. Routine screening for chlamydia and gonorrhea should be performed for women at high risk of acquiring sexually transmitted diseases. The practice of routine screening for BV in asymptomatic women who are at low risk for preterm delivery cannot be supported based on evidence from the literature. Routine screening for asymptomatic bacteriuria during pregnancy is cost-effective, particularly in high-prevalence populations. The results of antibiotic trials for the treatment of preterm labor have been inconsistent. In the absence of reasonable evidence that antimicrobial therapy leads to significant prolongation of pregnancy in the setting of preterm labor, antibiotics should be used only for protecting the neonate from group B streptococci sepsis. They should not be used for the purpose of prolonging pregnancy. Multiple investigations have shown that, in patients with preterm premature rupture of the membranes, prophylactic antibiotics are of value in prolonging the latent period between rupture of the membranes and onset of labor and in reducing the incidence of maternal and neonatal infection. The most extensively tested effective antibiotic regimen for prophylaxis involves erythromycin alone or in combination with ampicilln. Controversy still exists regarding the appropriate length and route of antibiotic prophylaxis.
基于生化、微生物学及临床证据，已证实生殖道感染与早产之间存在关联。理论上，病原菌可从下生殖道上行至子宫，由此引发的炎症会导致早产、胎膜破裂及分娩。越来越多的证据表明，早产和/或胎膜破裂是由生殖道中的微生物以及宿主对这些微生物的反应所触发的，即细胞因子和蛋白水解酶的释放。流行病学和体外研究并未证实感染与早产之间存在因果关系。然而，大量证据表明，治疗无症状菌尿症以及有症状的下生殖道感染，如细菌性阴道病（BV）、滴虫病、淋病和衣原体感染，将降低早产风险。根据目前的证据，发现阴道分泌物异常的孕妇应接受BV、滴虫、淋病和衣原体检测。检测呈阳性者应接受适当治疗。临床上建议在孕期对无症状菌尿症进行3至7天的抗生素治疗，以降低肾盂肾炎和早产风险。对于有感染性传播疾病高风险的女性，应进行衣原体和淋病的常规筛查。根据文献证据，无法支持对早产低风险的无症状女性进行BV常规筛查。孕期无症状菌尿症的常规筛查具有成本效益，尤其是在高发病率人群中。治疗早产的抗生素试验结果并不一致。在缺乏合理证据表明抗菌治疗能在早产情况下显著延长孕周的情况下，抗生素仅应用于保护新生儿免受B族链球菌败血症感染。不应将其用于延长孕周的目的。多项研究表明，对于胎膜早破的患者，预防性使用抗生素在延长胎膜破裂至临产的潜伏期以及降低母婴感染发生率方面具有价值。最广泛测试的有效预防性抗生素方案包括单独使用红霉素或与氨苄西林联合使用。关于抗生素预防的适当疗程和途径仍存在争议。
