As you’ve already ready, premature atrial contractions (PACs), abnormal early heartbeats that originate in the upper chambers of the heart, are frequently seen in utero, especially during
the second trimester. They can persist into the third trimester, but often go away during
that time or soon after birth. Bigeminy, for our othe r readers, means that every other beat is premature. There are two issues that can become concerning here.