Lisonkova Sarka, Sabr Yasser, Joseph K S
Department of Obstetrics and Gynaecology, University of British Columbia, and the Children's and Women's Hospital and Health Centre of British Columbia, Vancouver BC.
Department of Obstetrics and Gynaecology, University of British Columbia, and the Children's and Women's Hospital and Health Centre of British Columbia, Vancouver BC; Department of Obstetrics and Gynaecology, College of Medicine, King Saud University, Riyadh, Saudi Arabia; School of Population and Public Health, University of British Columbia, Vancouver BC.
J Obstet Gynaecol Can. 2014 Feb;36(2):116-122. doi: 10.1016/S1701-2163(15)30656-3.
Microbial invasion of the amniotic cavity (MIAC) can affect outcomes following rescue cerclage. We carried out a study to compare the diagnostic performance of the Gram stain and glucose tests for detecting subclinical MIAC.
We used individual-level data from published studies on Gram stain, glucose, and amniotic fluid culture among women with preterm labour. We calculated the sensitivity, specificity, area under the curve (AUC) and other indices, with amniotic fluid culture results used as the gold standard. The probability of infection using both tests as predictors was also estimated using logistic regression.
The rate of culture-confirmed MIAC was 11.8% (34 of 288 women). The Gram stain test yielded a sensitivity of 65% (95% CI 46% to 78%) and a specificity of 99% (95% CI 98% to 100%). A positive Gram stain or glucose test had a sensitivity of 88% (95% CI 72% to 96%) and a specificity of 87% (95% CI 82% to 90%), while a positive Gram stain and a positive glucose test had a sensitivity of 62% (95% CI 44% to 77%) and a specificity of 100% (95% CI 98% to 100%). The AUC for the tests were Gram stain 0.82 (95% CI 0.74 to 0.90), glucose 0.86 (95% CI 0.80 to 0.93), and combined Gram stain and glucose 0.92 (95% CI 0.86 to 0.98). Using the tests, singly or in combination, provided greater clinically important calibration, risk-stratification, and classification accuracy than using no tests.
Amniotic fluid Gram stain and/or glucose testing provides substantially improved performance for the diagnosis of subclinical MIAC compared with no testing.
羊膜腔微生物入侵（MIAC）会影响紧急宫颈环扎术后的结局。我们开展了一项研究，比较革兰氏染色和葡萄糖检测对亚临床MIAC的诊断性能。
我们使用了已发表研究中的个体水平数据，这些研究涉及早产女性的革兰氏染色、葡萄糖检测和羊水培养。我们计算了灵敏度、特异度、曲线下面积（AUC）及其他指标，以羊水培养结果作为金标准。还使用逻辑回归估计了将两种检测作为预测指标时的感染概率。
培养确诊的MIAC发生率为11.8%（288名女性中的34名）。革兰氏染色检测的灵敏度为65%（95%可信区间46%至78%），特异度为99%（95%可信区间98%至100%）。革兰氏染色或葡萄糖检测结果为阳性时，灵敏度为88%（95%可信区间72%至96%），特异度为87%（95%可信区间82%至90%）；革兰氏染色和葡萄糖检测结果均为阳性时，灵敏度为62%（95%可信区间44%至77%），特异度为100%（95%可信区间98%至100%）。各检测的AUC分别为：革兰氏染色0.82（95%可信区间0.74至0.90），葡萄糖0.86（95%可信区间0.80至0.93），革兰氏染色与葡萄糖联合检测0.92（95%可信区间0.86至0.98）。与不进行检测相比，单独或联合使用这些检测在临床重要校准、风险分层和分类准确性方面有更大提升。
与不进行检测相比，羊水革兰氏染色和/或葡萄糖检测在亚临床MIAC诊断方面的性能有显著改善。
