Mild prominence in both sides of the pelvis, measuring up to 7mm, is not uncommon in ultrasounds and is usually considered within normal range. It may be caused by various factors such as fluid accumulation or positioning during the scan. In most cases, it does not cause any issues or complications for the baby. However, it is important to follow up with your healthcare provider for further evaluation and monitoring. They will assess if there are any additional findings or concerns that require attention.