Are 3d ultrasounds during pregnancy safe?

Debated but gnrly ya: The question of whether or not ultrasound (US) can physically heat the tissue (because of multiple internal reflections & the focusing of the US beam) is a topic that is debated among scientists, but generally speaking, though, US is considered safe by the FDA / medical community. The max power in the systems is regulated by the FDA, & no proven harm has been demonstrated as yet. Need more studies