SAN JUAN, Puerto Rico — Puerto Rico on Tuesday held its first public hearing on a bill that aims to restrict abortions in the U.S. territory as powerful political leaders who support the measure seek to join a similar conservative push in the U.S. mainland.If approved, the bill would ban abortions starting at 22 weeks or when a doctor determines that a fetus is viable. The only exception would be if a woman’s life is in danger. Most U.S. states already have similar laws, unlike Puerto Rico, where abortions with no term limit are currently allowed.