The need for serial in-office non-stress tests (NSTs) adds significant burden to high-risk pregnancies and exacerbates care disparities.
We sought to determine the clinical interpretability, reactivity, and usability of a self-administered, wireless pregnancy monitoring device called INVU by Nuvo to enable patients to conduct NSTs from home.
Patients with high-risk singleton pregnancies ≥32 weeks of gestation and BMI< 50 kg/m2 were enrolled to perform clinically indicated NSTs remotely using the INVU device to replace in-office NSTs. The clinician reviewed NSTs in real-time via a web-based application and determined clinically interpretability and reactivity. Upon study completion, subjects completed the validated System Usability Scale (SUS).
We enrolled 34 high-risk patients at mean gestational age 34.5±1.1 weeks and BMI 35.8± 6.3 kg/m2. Fetal testing indications (of which patients could have >1) included advanced maternal age (n=14), body mass index ≥40kg/m (n=11), gestational diabetes, type A2 (n=10), chronic hypertension on antihypertensive medications (n=3), antiphospholipid syndrome (n=2), and other (n=9). Five consented patients failed to complete the device training. The remaining 29 patients had 131 qualifying remote NST sessions. INVU successfully obtained an interpretable NST in 93.9% (n=123) of appointments, of which 98.3% (n=121) were considered reactive. Patients avoided an in-office visit in 88.5% of visits. Twenty-three (79.3%) of patients who attempted at least 1 remote NST completed the SUS, with a mean score of 76.5 (± 15.9) out of 100, indicating “good” usability, with 22 (95.7%) agreeing they would prefer remote NSTs over in-office testing in a future pregnancy.
The INVU device showed excellent interpretability and usability for at-home NSTs in high-risk pregnancies, eliminating the need for an in-person visit in >88% of appointments. Further work is needed to determine how remote NSTs may relieve barriers to care and improve outcomes in high-risk pregnancies.

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