Intermountain Healthcare, Salt Lake City, UT; University of Utah Health, Salt Lake City, UT.
Intermountain Healthcare, Salt Lake City, UT; University of Utah Health, Salt Lake City, UT.
Am J Obstet Gynecol. 2020 Aug;223(2):244.e1-244.e12. doi: 10.1016/j.ajog.2020.02.012. Epub 2020 Feb 20.
The objective of the study was to compare interpretability of 2 intrapartum abdominal fetal heart rate-monitoring strategies. We hypothesized that an external fetal electrocardiography monitoring system, a newer technology using wireless abdominal pads, would generate more interpretable fetal heart rate data compared with standard external Doppler fetal heart rate monitoring (standard external monitoring).
We conducted a randomized controlled trial at 4 Utah hospitals. Patients were enrolled at labor admission and randomized in blocks based on body mass index to fetal electrocardiography or standard external monitoring. Two reviewers, blinded to study allocation, reviewed each fetal heart rate tracing. The primary outcome was the percentage of interpretable minutes of fetal heart rate tracing. An interpretable minute was defined as >25% fetal heart rate data present and no more than 25% continuous missing fetal heart rate data or artifact present. Secondary outcomes included the percentage of interpretable minutes of fetal heart rate tracing obtained while on study device only, the number of device adjustments required intrapartum, clinical outcomes, and patient/provider device satisfaction. We determined that 100 patients per arm (200 total) would be needed to detect a 5% difference in interpretability with 95% power.
A total of 218 women were randomized, 108 to fetal electrocardiography and 110 to standard external monitoring. Device setup failure occurred more often in the fetal electrocardiography group (7.5% [8 of 107] vs 0% [0 of 109] for standard external monitoring). There were no differences in the percentage of interpretable tracing between the 2 groups. However, fetal electrocardiography produced more interpretable fetal heart rate tracing in subjects with a body mass index ≥30 kg/m. When considering the percentage of interpretable minutes of fetal heart rate tracing while on study device only, fetal electrocardiography outperformed standard external monitoring for all subjects, regardless of maternal body mass index. Maternal demographics and clinical outcomes were similar between arms. In the fetal electrocardiography group, more device changes occurred compared with standard external monitoring (51% vs 39%), but there were fewer nursing device adjustments (2.9 vs 6.2 mean adjustments intrapartum, P < .01). There were no differences in physician device satisfaction scores between groups, but fetal electrocardiography generated higher patient satisfaction scores.
Fetal electrocardiography performed similarly to standard external monitoring when considering percentage of interpretable tracing generated in labor. Furthermore, patients reported overall greater satisfaction with fetal electrocardiography in labor. Fetal electrocardiography may be particularly useful in patients with a body mass index ≥30 kg/m.
本研究旨在比较两种产时腹部胎儿心率监测策略的可解释性。我们假设，一种使用无线腹部电极的新型外部胎儿心电图监测系统，与标准外部多普勒胎儿心率监测（标准外部监测）相比，将产生更具可解释性的胎儿心率数据。
我们在犹他州的 4 家医院进行了一项随机对照试验。患者在入院分娩时入组，并根据体重指数以块为单位进行随机分组，分为胎儿心电图组或标准外部监测组。两名审阅者对胎儿心率描记图进行了盲法审阅。主要结局是可解释的胎儿心率描记分钟数的百分比。可解释的 1 分钟定义为> 25%的胎儿心率数据存在，且连续缺失的胎儿心率数据或伪影不超过 25%。次要结局包括仅使用研究设备获得的可解释分钟数的百分比、产时所需设备调整的次数、临床结局和患者/提供者对设备的满意度。我们确定，每组需要 100 名患者（共 200 名），才能以 95%的效能检测出 5%的可解释性差异。
共有 218 名女性被随机分为胎儿心电图组（108 名）和标准外部监测组（110 名）。胎儿心电图组设备设置失败的发生率更高（7.5%[8/107] vs 0%[0/109]，标准外部监测组）。两组之间的可解释描记百分比没有差异。然而，对于 BMI≥30kg/m的患者，胎儿心电图产生了更多可解释的胎儿心率描记。当考虑仅使用研究设备的可解释分钟数百分比时，无论母体 BMI 如何，胎儿心电图在所有受试者中的表现均优于标准外部监测。产妇人口统计学和临床结局在两组之间相似。在胎儿心电图组中，与标准外部监测相比，设备变化发生的频率更高（51% vs 39%），但护理设备调整的次数更少（产时平均调整 2.9 次 vs 6.2 次，P<.01）。两组医生对设备的满意度评分没有差异，但胎儿心电图的患者满意度评分更高。
在考虑产时产生的可解释描记百分比时，胎儿心电图的表现与标准外部监测相似。此外，患者在分娩时报告对胎儿心电图的总体满意度更高。胎儿心电图在 BMI≥30kg/m的患者中可能特别有用。
