Heffner L J, Sherman C B, Speizer F E, Weiss S T
Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital, Boston, Massachusetts.
Obstet Gynecol. 1993 May;81(5 ( Pt 1)):750-7.
To determine the magnitude of risk for preterm labor associated with specific clinical and environmental factors.
Using a case-control design, 266 women with preterm labor and 512 controls were interviewed and their medical records reviewed. Crude and adjusted odds ratios were calculated for each risk factor. Population-attributable risks were estimated.
Third-trimester bleeding, twin gestation, and chorioamnionitis at presentation were strongly associated with preterm labor (odds ratios 11.2-48.3). A history of a prior preterm delivery, vaginal bleeding in the first or second trimester, maternal diethylstilbestrol exposure, uterine anomalies, and urinary tract infection during pregnancy were associated to a lesser extent (odds ratios 1.6-5.4), as were cigarette smoking and drug use (odds ratios 2.0 and 3.0). Cases who had preterm labor preceded by premature rupture of the membranes had a substantially higher risk of preterm labor if chorioamnionitis, vaginal bleeding early in pregnancy, or urinary tract infection was present. By contrast, women who had intact membranes at the onset of preterm labor carried higher risk when twin gestation, placental abruption, or uterine anomaly was present. The highest population-attributable risks for preterm labor were found in patients with a twin gestation or third-trimester bleeding.
Programs to reduce the preterm delivery rate should consider the attributable risks for the factors they are intended to modify. The attributable risks we obtained suggest that medical strategies to reduce the impact of the clinical variables, especially multiple gestation, and educational programs to decrease smoking and drug use should reduce the preterm delivery rate.
确定与特定临床和环境因素相关的早产风险程度。
采用病例对照设计，对266例早产妇女和512例对照进行访谈，并查阅她们的病历。计算每个风险因素的粗比值比和调整后比值比。估计人群归因风险。
孕晚期出血、双胎妊娠和就诊时的绒毛膜羊膜炎与早产密切相关（比值比为11.2 - 48.3）。既往早产史、孕早期或孕中期阴道出血、母亲暴露于己烯雌酚、子宫异常和孕期尿路感染的相关性较小（比值比为1.6 - 5.4），吸烟和吸毒的相关性也较小（比值比分别为2.0和3.0）。胎膜早破后发生早产的病例，如果存在绒毛膜羊膜炎、孕早期阴道出血或尿路感染，则早产风险显著更高。相比之下，早产开始时胎膜完整的妇女，若存在双胎妊娠、胎盘早剥或子宫异常，则风险更高。早产人群归因风险最高的是双胎妊娠或孕晚期出血的患者。
降低早产率的项目应考虑其旨在改变的因素的归因风险。我们获得的归因风险表明，降低临床变量尤其是多胎妊娠影响的医学策略，以及减少吸烟和吸毒的教育项目，应能降低早产率。
