Baby’s HR 200bpm

Aubrey • DS born May 21, 2018, surprise with #2 due Aug 2019

Went to a 12 week ultrasound s few weeks ago and baby’s heart rate was 200bpm. Have gone back a couple times and the HR is still 200bpm. The doctor said she had never seen this before and put a call into the specialist and he hasn’t seen it either. Has anyone ever come across this in the first trimester? What did they do for you and baby?