Ravi Mini, Beljorie Mercy, El Masry Karim
Department of Obstetrics and Gynecology, Mafraq Hospital , Abu Dhabi , United Arab Emirates.
J Matern Fetal Neonatal Med. 2019 Dec;32(23):3909-3914. doi: 10.1080/14767058.2018.1476485. Epub 2018 May 28.
The objective of this study is to compare the qualitative fFN test at 50 ng/ml threshold to novel methods for assessing risk of imminent sPTB in women with symptoms of preterm labor (PTL): (1) quantitative fetal fibronectin (qfFN) at four thresholds: 10, 50, 200, and 500 ng/ml; and (2) qualitative PAMG-1 test. Consecutive patients presenting with singleton pregnancies, signs of PTL, gestational age 23.1-34.6, intact membranes, no coitus within 24 h, and cervical dilation ≤3 cm. fFN was performed as standard of care, while clinicians were blinded to the qfFN and PAMG-1 test results. qfFN accuracy was evaluated at four thresholds of 10, 50, 200, and 500 ng/ml for its ability to predict imminent spontaneous preterm delivery (sPTD) ≤ 7 and ≤14 d from the time of sample collection. The PAMG-1 test was evaluated based on its qualitative result for the same delivery endpoints. Seventy-two patients were analyzed. Fifty-seven percent of patients had an fFN concentration of <10 ng/ml fFN; 75% < 50 ng/ml; 92% < 200 ng/ml; 97% < 500 ng/ml. The SN, SP, PPV, and NPV for fFN at each of the four cutoffs for sPTB ≤7 d: 10 ng/ml: 67%, 58%, 6%, 98%; 50 ng/ml: 67%, 77%, 11%, 98%; 200 ng/ml: 33%, 93%, 17%, 97%; 500 ng/ml: 0%, 97%, 0%, 96%. The PAMG-1 test was positive in 7% of patients. SN, SP, PPV, and NPV for PAMG-1 for sPTD ≤7 d were 67%, 96%, 40%, and 99%, respectively. Compared with qfFN, the PAMG-1 test is a better predictor of spontaneous delivery within 7 d while maintaining a very high negative predictive value. The PAMG-1 test is an easy-to-use bedside test that provides rapid results, does not require a speculum examination, can be used after vaginal exam and coitus and does not require specialized equipment to analyze results. As to be expected, compared with the conventional cutoff of fFN (50 ng/ml), a higher fFN cutoff of 200 ng/ml does seem to increase the PPV of the test, but this comes at a cost to the fFN test's SN and NPV, rendering it of little to no advantage in clinical practice.
本研究的目的是将阈值为50 ng/ml的定性胎儿纤连蛋白（fFN）检测与评估有早产（PTL）症状女性即将发生自发性早产（sPTB）风险的新方法进行比较：（1）四个阈值（10、50、200和500 ng/ml）的定量胎儿纤连蛋白（qfFN）；以及（2）定性PAMG-1检测。连续纳入单胎妊娠、有PTL体征、孕龄23.1 - 34.6周、胎膜完整、24小时内无性交且宫颈扩张≤3 cm的患者。fFN检测作为标准治疗方法，而临床医生对qfFN和PAMG-1检测结果不知情。评估qfFN在10、50、200和500 ng/ml这四个阈值下预测自样本采集时间起≤7天和≤14天即将发生自发性早产分娩（sPTD）的能力。基于PAMG-1检测针对相同分娩终点的定性结果进行评估。分析了72例患者。57%的患者fFN浓度<10 ng/ml；75%<50 ng/ml；92%<200 ng/ml；97%<500 ng/ml。sPTB≤7天时，fFN在四个临界值处的灵敏度（SN）、特异度（SP）、阳性预测值（PPV）和阴性预测值（NPV）：10 ng/ml：67%、58%、6%、98%；50 ng/ml：67%、77%、11%、98%；200 ng/ml：33%、93%、17%、97%；500 ng/ml：0%、97%、0%、96%。7%的患者PAMG-1检测呈阳性。sPTD≤7天时，PAMG-1的SN、SP、PPV和NPV分别为67%、96%、40%和99%。与qfFN相比，PAMG-1检测在7天内自发性分娩的预测方面更好，同时保持非常高的阴性预测值。PAMG-1检测是一种易于使用的床边检测方法，能快速得出结果，无需窥器检查，可在阴道检查和性交后使用，且分析结果不需要专门设备。正如预期的那样，与fFN的传统临界值（50 ng/ml）相比，200 ng/ml的较高fFN临界值似乎确实增加了检测的PPV，但这是以牺牲fFN检测的SN和NPV为代价的，使其在临床实践中几乎没有优势。
