Department of Obstetrics and Gynecology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, USA.
Acta Obstet Gynecol Scand. 2024 Nov;103(11):2252-2263. doi: 10.1111/aogs.14899. Epub 2024 Sep 17.
Intra-amniotic inflammation is causally linked to spontaneous preterm labor. The gold standard for the diagnosis of intra-amniotic inflammation is the determination of an amniotic fluid profile obtained from transabdominal amniocentesis, which is invasive. Cervicovaginal fluid fetal fibronectin (fFN) is a widely-used predictive biomarker for spontaneous preterm labor. The aims of this study are to determine (1) whether a quantitative cervicovaginal fluid fFN test can be used to identify the presence of intra-amniotic inflammation; and (2) an appropriate cut-off value of a cervicovaginal fluid fFN concentration for the identification of intra-amniotic inflammation.
This prospective cohort study included 78 patients with preterm labor and intact membranes who had a sample collected for quantitative cervicovaginal fluid fFN measurement and underwent transabdominal amniocentesis. Intra-amniotic inflammation was defined as an amniotic fluid interleukin-6 concentration ≥2.6 ng/mL. Clinicians were masked from the results of cervicovaginal fluid fFN and amniotic fluid interleukin-6 concentrations. Logistic regression analysis was used to determine which factors were significant predictors of intra-amniotic inflammation. The diagnostic indices of the cervicovaginal fluid fFN test for the identification of intra-amniotic inflammation were calculated.
(1) Frequency of intra-amniotic inflammation was 26.9% (21/78); (2) the higher the cervicovaginal fluid fFN concentration, the greater the risk of intra-amniotic inflammation (p < 0.001); (3) cervicovaginal fluid fFN concentration ≥125 ng/mL had an area under the curve of 0.91 (95% confidence interval: 0.83-0.96) for the identification of intra-amniotic inflammation with 100% sensitivity, 100% negative predictive value, 82.46% specificity and a positive likelihood ratio of 5.7; and (4) cervicovaginal fluid fFN cut-off of 125 ng/mL had a significant higher predictive performance than the traditional cut-off (50 ng/mL) for the identification of intra-amniotic inflammation.
Quantitative cervicovaginal fluid fFN with a cut-off of 125 ng/mL had a high sensitivity and a negative predictive value as well as a positive likelihood ratio for the identification of intra-amniotic inflammation. Its high sensitivity and negative predictive value can be used to decrease an index of suspicion of intra-amniotic inflammation. This test may be useful as an initial assessment test to select appropriate patients for amniocentesis to determine intra-amniotic inflammation.
羊膜内炎症与自发性早产劳动有因果关系。羊膜内炎症诊断的金标准是从经腹羊膜穿刺术获得的羊水分析，这是一种侵入性的方法。宫颈阴道液胎儿纤维连接蛋白（fFN）是预测自发性早产劳动的一种广泛使用的预测生物标志物。本研究的目的是确定（1）定量宫颈阴道液 fFN 试验是否可用于识别羊膜内炎症的存在；（2）宫颈阴道液 fFN 浓度的适当截断值用于识别羊膜内炎症。
这项前瞻性队列研究包括 78 例早产且胎膜完整的患者，他们采集了定量宫颈阴道液 fFN 测量和经腹羊膜穿刺术样本。羊膜内炎症定义为羊水白细胞介素-6 浓度≥2.6ng/ml。临床医生对宫颈阴道液 fFN 和羊水白细胞介素-6 浓度的结果进行了屏蔽。逻辑回归分析用于确定哪些因素是羊膜内炎症的显著预测因子。计算了宫颈阴道液 fFN 试验识别羊膜内炎症的诊断指标。
（1）羊膜内炎症的频率为 26.9%（21/78）；（2）宫颈阴道液 fFN 浓度越高，羊膜内炎症的风险越大（p<0.001）；（3）宫颈阴道液 fFN 浓度≥125ng/ml 对羊膜内炎症的识别具有 0.91（95%置信区间：0.83-0.96）的曲线下面积，具有 100%的敏感性、100%的阴性预测值、82.46%的特异性和 5.7 的正似然比；（4）宫颈阴道液 fFN 截断值为 125ng/ml 对羊膜内炎症的识别具有比传统截断值（50ng/ml）更高的预测性能。
定量宫颈阴道液 fFN 的截断值为 125ng/ml 对羊膜内炎症具有高敏感性和阴性预测值，以及正似然比。其高敏感性和阴性预测值可用于降低对羊膜内炎症的怀疑指数。该试验可用作初始评估试验，以选择适当的患者进行羊膜穿刺术以确定羊膜内炎症。
