Teleultrasound for pre-natal diagnosis: A validation study

There are no large validation trials comparing teleultrasound to on-site ultrasound. We aim to compare the sensitivity and accuracy of teleultrasound and demonstrate that teleultrasound is not inferior to on-site ultrasound in the pre-natal diagnosis of fetal anomalies.

All targeted ultrasounds performed between November 2010 and December 2012 were considered. We excluded studies performed at less than 17 weeks' gestation, on multiple gestations and for reasons other than an anatomical survey. Post-natal diagnoses were obtained from a state level mandatory birth defects surveillance programme. Descriptive statistics (sensitivity, specificity, positive and negative predictive values and accuracy) were calculated for both groups. A test of non-inferiority was performed, with the non-inferiority difference set at 0.15.

The teleultrasound and on-site ultrasound groups consisted of 2368 and 3145 studies, respectively. The sensitivity of teleultrasound and on-site ultrasound was 57.46% and 76.57%, and the accuracy was 95.9% and 90.97%, respectively. The observed sensitivity difference was -0.1911. The accuracy, specificity, positive and negative predictive values of teleultrasound are similar to on-site ultrasound.

Teleultrasound is inferior to on-site ultrasound in the detection of fetal anomalies; however, it has improved accuracy, as well as higher negative and positive predictive values. A negative teleultrasound is more likely to identify a non-anomalous fetus, and a positive teleultrasound is more likely to correctly identify an anomalous fetus.

Teleultrasound has an important role in pre-natal diagnosis for those patients unable or unwilling to travel for an on-site ultrasound.