Q&A: At 22 weeks, my baby's heart rate was irregular. Is this a sign of an abnormality?

At 22 weeks there is still a lot of maturation of your baby's organs going on. The baby's heart is no exception, especially the electrical conduction nerve network that is responsible for rate and rhythm. Before ultrasound, we rarely caught this type of problem, but then we began seeing it in the second trimester, prompting a Maternal-Fetal Medicine consultation and fetal echocardiograms. And they always came back normal, the arrhythmias resolved themselves mysteriously, and the babies did fine. We now know it isn't uncommon to see arrhythmias in the second trimester.

I was once doing an ultrasound on a patient at about 21 weeks. The mother and father were watching the screen with me when the heart actually stopped. The mother's eyes got big, the father's eyes got big, my eyes got big. A long two to three seconds later, the heart cranked back up again. This baby did fine, too. Pretty scary, but this is a dramatic example of how something that looks so abnormal is very normal while the heart's electrical pathways are maturing.

It doesn't hurt, though, to let your health care provider know about your concerns so that he or she can reassure you that everything else looks normal, or make suggestions for further testing.