Validation that INVU Is Effective for Self-Administered NST

The following summary provides a high-level overview of a peer-reviewed study describing a novel method for uterine contraction monitoring designed to enable remote, self-administered nonstress testing.

Background:

Serial fetal monitoring recommended for women with high-risk pregnancies places a substantial burden on patients and may disproportionately affect underprivileged and rural populations. Telehealth solutions that enable fetal surveillance from home have the potential to improve access to care and promote health equity.

Although a wireless pregnancy monitor had previously been validated for remote fetal and maternal heart rate monitoring, effective remote nonstress testing also requires accurate detection of uterine contractions. This study addresses that need.

Objective:

The objective of this study was to describe and validate a novel algorithm that uses biopotential and acoustic signals to noninvasively detect uterine contractions via a wireless pregnancy monitoring device.

Study Design:

This was a prospective, open-label, two-center study conducted in women with singleton pregnancies at ≥32 weeks’ gestation who were in the first stage of labor.

          1. Uterine contractions were simultaneously recorded using:

• • The wireless pregnancy monitor

  • An intrauterine pressure catheter (IUPC)

  • In a subset, external tocodynamometry (TOCO)

  
  

  2. The study included a training phase and a validation phase.

  3. Three maternal–fetal medicine specialists, blinded to data source, independently identified contractions.

  4. Performance metrics included positive agreement and false-positive rates, compared with IUPC.

Results:

Participants: 118 women (40 training phase; 78 validation phase), mean gestational age 38.6 weeks.

Training phase:

Positive agreement: 88.4%

False-positive rate: 15.3%

Validation phase:

Positive agreement: 84.8%

False-positive rate: 24.8%

In participants monitored only with the wireless monitor and IUPC:

Positive agreement: 89.0%

In participants monitored with all three devices:

Positive agreement of the wireless monitor was significantly higher than TOCO

False-positive rate was higher than TOCO

Unlike TOCO, the performance of the wireless monitor was not affected by body mass index.

Conclusion:

This novel algorithm enables accurate, noninvasive monitoring of uterine activity using a wireless pregnancy monitoring device designed for self-administration at home. The method was found to be more accurate than standard tocodynamometry and unaffected by maternal body mass index. Combined with previously reported remote fetal heart rate monitoring capabilities, this approach supports a comprehensive telehealth solution for remote nonstress testing.

The full article is available at:

https://www.ajog.org/article/S0002-9378(21)01211-4/abstract

• Novel uterine contraction monitoring to enable remote, self-administered non-stress testing

• American Journal of Obstetrics & Gynecology 2022