The Republican-led Iowa House voted on Thursday to require doctors to perform an ultrasound on any woman seeking an abortion and let her see the image and hear the fetus' heartbeat.
The bill passed by a 57-39 vote after several hours of debate, though it is not likely to pass in the Democratic-controlled Senate.
"It is my belief that we are defending two lives here, both a mother and a child," Republican Representative Joel Fry said to open the debate.
Several states have enacted similar measures, though some go further, requiring the woman to view the image during the ultrasound.
Supporters of Iowa's measure, which would carry possible licence discipline and a fine for doctors who violate it, claimed it would provide crucial information to women making an irrevocable decision.
Opponents argued that it represented a government overreach into women's healthcare decisions, adding that widening access to family planning services would be more prudent.
"This proposed bill is just another effort by some lawmakers to shame a woman who has made a difficult decision to end her pregnancy," Democratic Representative Mary Mascher said.
A study published in the January 2014 issue of the journal Obstetrics and Gynecology showed nearly 99 percent of women went ahead with an abortion after voluntarily viewing an ultrasound image of the fetus.
(Editing by Curtis Skinner and Clarence Fernandez)