Jen Cardinal posted the incredible video to YouTube.
According to Cardinal, her and her husband were at their 14 week ultrasound when the baby appeared to clap its hands. They had their doctor rewind the image so that they could sing along to the baby's apparent clapping.
"The experience is one I'll never forget, the baby clapped three times, then the doctor rewound and scrubbed it while we sang. No mystery. It was amazing," Cardinal wrote on YouTube.
Mobile users can watch the video here: https://youtu.be/mR6POuFfFNU