Objectives: To identify all available studies assessing the use of portable ultrasound devices for pregnant women, with the specific aim of finding evidence for devices used to determine gestational age and their validity when compared to conventional ultrasound machines. We also wanted to determine what portable ultrasound models are commercially available for obstetric use. 

Design: Systematic scoping review

Primary and secondary outcome measures: Extracted variables included study design, population, method of ultrasound measurement, devices used and whether studies formally validated accuracy against conventional ultrasound

Results: We searched four databases – Medline, Embase, CINAHL, and Maternal and Infant Care. In total, 56 studies from 34 countries were identified; most were observational studies. Across all studies, 27 different portable ultrasound models (from 17 manufacturers) were evaluated. Twenty-one studies assessed use of portable ultrasound for evaluating fetal characteristics or estimating gestational age, and 10 of these were formal validation studies. In total, six portable devices have been validated for gestational age estimation against a conventional ultrasound comparator. The web searches identified 102 portable devices (21 manufacturers). These were a mix of handheld devices that connected to a phone or computer, or laptop-style portable ultrasound devices. Prices ranged from $1,190 to $30,000 USD and weight ranged from 0.9 kg to 13.0 kg.

Conclusion: While the number of commercially available portable ultrasound devices continues to grow, there remains a lack of peer-reviewed, quality evidence demonstrating their accuracy and validity when compared to conventional ultrasound machines. This review identified some models that may be useful in gestational age estimation in low-resource settings, but more research is required to help implement the technology at scale.

File 1. Commercially available models

- This table was formed by searching the online websites and stores to identify commercially available portable ultrasound devices

- Manufacturers were identified by a comination of general and targeted online searches

- Specific paramaters to be extracted were identified prior to commencement of the search (these form the columns in the dataset)

- Eight of these were the suggested or requirements of obstetric ultrasound equipment as identified in the World Health Organization (WHO) report 'WHO recommendations on antenatal care for a positive pregnancy experience: ultrasound examination'

- Best attempts were made to identify all data, though for a lot of devices the full set of paramaters could not be extracted from their online information, hence some fields do not have results

File 2. Results of scoping review

- This file is the result of the systematic scoping review conducted as part of this research project

- Articles were identified via a literature search process described elsewhere

- Parameters for extraction were agreed upon by a select number of members from the research team

- Data was taken directly from the article, with allocations then made to various classifications. These classifications used pre-determined options to ensure consistency

- All data was extracted by two independent researchers, with any conflicts settled by a third independent reviewer.

Files may be opened and used in Microsoft Excel program.