Abortion Opponents Hear a ‘Heartbeat.’ Most Experts Hear Something Else.

Embedded in abortion laws in Texas are disputed assertions about embryonic development and the procedure’s risks. Chief among them: whether the early embryo has a heart.

By Roni Caryn Rabin
Feb. 14, 2022

The Texas law banning abortions after about six weeks of pregnancy is based on a singular premise disputed by many medical experts: that once an ultrasound detects electrical cardiac activity in an embryo, its heart is beating and a live birth is on the way.

At this very early stage of a pregnancy, however, the embryo is the size of a pomegranate seed and has only a primitive tube of cardiac cells that emit electric pulses and pump blood.