My 20 weeks ultrasound was unable to see the fetus right and left ventricles of the heart

I am so sorry to hear that you are experiencing this concern.

There are several things that are looked for in regard to baby's heart during the 20 weeks scan, but often times a scan will need to be repeated a few weeks later to confirm any findings. This is because there can be a small percentage of situations that just don't get seen well enough at 20 weeks to make an accurate determination.

What did your doctor say to you about it? Have they scheduled another scan in a few weeks time?