Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY.
Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY.
Am J Obstet Gynecol. 2016 May;214(5):646.e1-6. doi: 10.1016/j.ajog.2016.01.160. Epub 2016 Feb 28.
Fetal fibronectin (fFN) is used as a biomarker for preterm delivery. Currently, its use is discouraged if there has been vaginal manipulation in the previous 24 hours.
Our objective is to determine if there are differences between fFN results before and after vaginal manipulation in the form of sterile vaginal exam or transvaginal ultrasound.
This was a prospective observational cohort study at a single center of women between 22-33 6/7 weeks at risk for preterm delivery due to: (1) a history of preterm delivery, short cervix, or multifetal gestation; or (2) symptoms of preterm labor. We excluded women with vaginal bleeding or infection, placenta previa, ruptured membranes, cervical dilation >3 cm, or any form of vaginal manipulation in the previous 24 hours. Specimen A was collected prior to planned vaginal exam or transvaginal ultrasound and specimen B was collected within 4 hours. The agreement between specimens A and B was assessed using descriptive statistics. Test characteristics of specimens A and B using the outcome of preterm delivery (<37 weeks) were calculated.
In all, 310 specimen pairs from 237 women were collected. Specimen A was positive in 37 (12%) instances and negative in 273 (88%) while specimen B was positive in 39 (13%) and negative in 271 (87%). There were discordant results in 26 specimen pairs. Of these, 14 (5%) negative specimen A results subsequently became positive for specimen B, and 12 (32%) positive specimen A results became negative for specimen B. Overall, there was a 92% agreement between specimens A and B (confidence interval, 88-94%). The specificity of specimens A and B for preterm birth was 90% vs 89%, respectively, with a negative predictive value of 87% for both. The false-negative rate was 12.8% for specimen A and 13.3% for specimen B.
There is a moderately high degree of agreement between prevaginal and postvaginal manipulation fFN results. Their test characteristics for evaluating preterm birth are similar with strong specificity and negative predictive values, and their false-negative rates are not clinically different. Consideration should be made to the utilization of postvaginal manipulation fFN when a prevaginal manipulation specimen is not available.
胎儿纤维连接蛋白（fFN）可用作早产的生物标志物。目前，如果在过去 24 小时内进行了阴道操作，则不建议使用。
我们的目的是确定无菌阴道检查或经阴道超声检查前后 fFN 结果是否存在差异。
这是一项单中心前瞻性观察队列研究，纳入了 22-33 6/7 周有早产风险的妇女：（1）有早产史、宫颈短或多胎妊娠；或（2）有早产症状。我们排除了阴道出血或感染、前置胎盘、胎膜破裂、宫颈扩张>3cm 或过去 24 小时内有任何形式的阴道操作的妇女。标本 A 在计划进行阴道检查或经阴道超声检查之前采集，标本 B 在 4 小时内采集。使用描述性统计评估标本 A 和 B 之间的一致性。使用早产（<37 周）的结果计算标本 A 和 B 的测试特征。
共采集了 237 名妇女的 310 对标本。标本 A 阳性 37 例（12%），阴性 273 例（88%），标本 B 阳性 39 例（13%），阴性 271 例（87%）。26 对标本存在不一致的结果。其中，14 例（5%）阴性标本 A 结果随后标本 B 转为阳性，12 例（32%）阳性标本 A 结果标本 B 转为阴性。总体而言，标本 A 和 B 之间的一致性为 92%（置信区间，88-94%）。标本 A 和 B 对早产的特异性分别为 90%和 89%，阴性预测值均为 87%。标本 A 的假阴性率为 12.8%，标本 B 的假阴性率为 13.3%。
阴道操作前后 fFN 结果之间存在较高的一致性。评估早产时，它们的测试特征具有相似的特异性和阴性预测值，且假阴性率无临床差异。当无法获得阴道操作前的标本时，应考虑使用阴道操作后的 fFN。
