20 wks. pregnant & baby has fetal arrhythmia

Hello. I am currently 20 weeks and was told that my daughter has fetal arrhythmia. Her HR was 145 bmp. Her HR is not considered brady/tachy. The Dr. said that the rhythm sounded like it was taking a 'pause' in between the beats. I am scheduled to get a fetal echo in a couple of weeks. Is this something I should be concerned with? What irregularity could this be? *They saw a good view of the 4-chamber heart, which he said r/o 85% of heart defects. Thank you.

[EchoTech]

I am not a doctor.

I do perform fetal echos.  Not knowing anything else, I'd be highly suspicious of  Pre Atrial Contractions which is caused when the left atrium fires off prematurely and causes a skipped beat.  This in itself is not a major problem.  The fetal echo might be able to show the heart well enough to see if the PFO flap is extra long (tissue that will eventually form the interatrial septum, but while the baby is inside, it can be loose) that can sometimes bang up against the roof of the atrium and cause a PAC.  I've also heard  that since the baby is still not fully developed, neither is the conduction system, so sometimes it will throw a PAC.  The most important thing is if the beat is really slow or really fast for a long time, or the baby is not moving, then get to the doctor in an immediate fashion.  This all a guess since I haven't done your fetal echo or know any of your history, but this is a common scenario that I've seen before.

Good luck.