1. The formula used for comparison with JSS Formula in our study was modified Shukla formula, which generally falls short of JSS formula.

2. Though ultrasound is increasingly being used to report the tip of the umbilical venous catheter, it is not universal due to availability of machines/skilled personnel. Regarding usage of lateral view, we differ regarding it being better. We have recently conducted a retrospective analysis of 140 X-rays for inter- and intra-rater agreement between horizontal-dorsal-decubitus (lateral) vs supine X-ray in determining the optimal localization of the tip position. This study showed a fair agreement (unpublished data) between both inter- and intra-raters with supine X-ray (k=0.6) and poor inter- and intra- rater agreement on lateral X-ray ( k=0.29).

3. We agree with the reader regarding the possibility of migration of the catheter, and we did not collect data for this time duration. The average turnaround time for chest X-ray is approximately 30 minutes in our unit, and all X-rays were taken with in an hour of insertion.