Background

The serial fetal monitoring recommended for women with high-risk pregnancies places a substantial burden on the patient, often disproportionately affecting underprivileged and rural populations. A telehealth solution that can empower pregnant women to obtain recommended fetal surveillance from the comfort of their own home has the potential to promote health equity and improve outcomes. We have previously validated a novel, wireless pregnancy monitor that can remotely capture fetal and maternal heart rates. However, such a device must also detect uterine contractions if it is to be used to robustly conduct remote nonstress tests.

Objective

This study aimed to describe and validate a novel algorithm that uses biopotential and acoustic signals to noninvasively detect uterine contractions via a wireless pregnancy monitor.

Study Design

A prospective, open-label, 2-center study evaluated simultaneous detection of uterine contractions by the wireless pregnancy monitor and an intrauterine pressure catheter in women carrying singleton pregnancies at ≥32 0/7 weeks’ gestation who were in the first stage of labor (ClinicalTrials.gov Identifier: NCT03889405). The study consisted of a training phase and a validation phase. Simultaneous recordings from each device were passively acquired for 30 to 60 minutes. In a subset of the monitoring sessions in the validation phase, tocodynamometry was also deployed. Three maternal-fetal medicine specialists, blinded to the data source, identified and marked contractions in all modalities. The positive agreement and false-positive rates of both the wireless monitor and tocodynamometry were calculated and compared with that of the intrauterine pressure catheter.

Results

A total of 118 participants were included, 40 in the training phase and 78 in the validation phase (of which 39 of 78 participants were monitored simultaneously by all 3 devices) at a mean gestational age of 38.6 weeks. In the training phase, the positive agreement for the wireless monitor was 88.4% (1440 of 1692 contractions), with a false-positive rate of 15.3% (260/1700). In the validation phase, using the refined and finalized algorithm, the positive agreement for the wireless pregnancy monitor was 84.8% (2722/3210), with a false-positive rate of 24.8% (897/3619). For the subgroup who were monitored only with the wireless monitor and intrauterine pressure catheter, the positive agreement was 89.0% (1191/1338), with a similar false-positive rate of 25.4% (406/1597). For the subgroup monitored by all 3 devices, the positive agreement for the wireless monitor was significantly better than for tocodynamometry (P<.0001), whereas the false-positive rate was significantly higher (P<.0001). Unlike tocodynamometry, whose positive agreement was significantly reduced in the group with obesity compared with the group with normal weight (P=.024), the positive agreement of the wireless monitor did not vary across the body mass index groups.

Conclusion

This novel method to noninvasively monitor uterine activity, via a wireless pregnancy monitoring device designed for self-administration at home, was more accurate than the commonly used tocodynamometry and unaffected by body mass index. Together with the previously reported remote fetal heart rate monitoring capabilities, this added ability to detect uterine contractions has created a complete telehealth solution for remote administration of nonstress tests.

中文翻译：

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新型子宫收缩监测可实现远程、自我管理的非压力测试

背景

为高危妊娠妇女推荐的连续胎儿监测给患者带来了沉重的负担，通常对贫困人口和农村人口造成不成比例的影响。一种远程医疗解决方案可以使孕妇在自己舒适的家中获得推荐的胎儿监测，这有可能促进健康公平并改善结果。我们之前已经验证了一种新颖的无线妊娠监测仪，它可以远程捕获胎儿和产妇的心率。然而，如果要使用这种设备来稳健地进行远程非压力测试，它还必须检测子宫收缩。

客观的

本研究旨在描述和验证一种新算法，该算法使用生物电势和声学信号通过无线妊娠监测器无创检测子宫收缩。

学习规划

一项前瞻性、开放标签、2 中心研究评估了在 ≥ 32 0/7 周单胎妊娠且处于第一产程的单胎妊娠妇女中，无线妊娠监测仪和宫内压导管同时检测子宫收缩的情况。 ClinicalTrials.gov 标识符：NCT03889405）。该研究包括训练阶段和验证阶段。被动地从每个设备获取同时记录 30 到 60 分钟。在验证阶段的一部分监控会话中，还部署了胎压计。三名母胎医学专家对数据源视而不见，识别并标记了所有方式的宫缩。

结果

总共包括 118 名参与者，其中 40 名处于训练阶段，78 名处于验证阶段（其中 78 名参与者中的 39 名同时被所有 3 台设备监测），平均胎龄为 38.6 周。在训练阶段，无线监护仪的阳性率为 88.4%（1692 次宫缩中的 1440 次），假阳性率为 15.3% (260/1700)。在验证阶段，使用完善和最终确定的算法，无线妊娠监测仪的阳性一致性为 84.8%（2722/3210），假阳性率为 24.8%（897/3619）。对于仅使用无线监测器和宫内压导管监测的亚组，阳性一致性为 89.0% (1191/1338)，假阳性率为 25.4% (406/1597)。对于所有 3 个设备监控的子组，P <.0001)，而假阳性率明显较高( P <.0001)。与生育力测定法不同，肥胖组与正常体重组相比，其阳性一致性显着降低（P = 0.024），无线监测器的阳性一致性在体重指数组之间没有变化。

结论

这种通过专为在家自我管理而设计的无线妊娠监测设备无创监测子宫活动的新方法比常用的宫缩测力法更准确，并且不受体重指数的影响。连同之前报道的远程胎心率监测功能，这种增加的检测子宫收缩的能力为远程管理非压力测试创造了一个完整的远程医疗解决方案。