Incorporating personal-device-based point-of-care ultrasound into obstetric care: a validation study

Background: Personal-device-based point-of-care-ultrasound (P-POCUS) probes plug directly into a cell phone or tablet to function as its display, creating the potential to increase access to obstetric ultrasonography in complex healthcare settings (COVID units, low resource settings); however, new technology must be proven to be reliable in the obstetric setting before integrating into practice.

Objective: To evaluate the intraclass correlation (reliability) of personal-device-based-point-of-care-ultrasound devices as compared with standard ultrasound machines in obstetrics.

Study design: This was a prospective, observational study of patients between 19-39 weeks gestation in an urban, prenatal ultrasound diagnosis center. Each patient underwent assessment by an expert sonographer using standard ultrasound machines and personal-device-based-point-of-care-ultrasound devices to determine estimated fetal weight. The statistical reliability and agreement between the estimated fetal weights was assessed through intraclass correlation coefficients, Bland-Altman plots, and Pearson correlation coefficients.

Results: 100 paired sets of scans were performed from October 2020 to December 2020. For the estimated fetal weights, there was near-perfect agreement, with an intraclass correlation coefficient of 0.99 (P<.0001). Bland-Altman analysis showed an average difference of 53 grams, with 95% limit of agreement between -178 grams and 283 grams. Pearson correlation showed near-perfect correlation between the measurements (r=0.99, P<.0001).

Conclusion: personal-device-based point-of-care-ultrasound devices are reliable tools for performing basic obstetrical ultrasound and have the potential to increase access to obstetrical ultrasound worldwide.