Senators voted 29-16 Friday to reject legislation that sought to define as a human being "any organism with the genome of homo sapiens." The "personhood" status would include a developing embryo from the moment of conception, whether inside or outside the womb.
A handful of states are considering similar proposals, and the measure generated an intense lobbying campaign from abortion opponents and people who favor abortion rights.
Sen. Curtis Olafson, a Republican, spoke out frequently against the bill, saying it would make it difficult for doctors to treat problem pregnancies that could threaten the woman's life because both she and her unborn child would have equal status under the law.
At a Senate hearing on the legislation, two reproductive endocrinologists testified that the bill would complicate the practice of in vitro fertilization, which involves removing eggs from a woman's body, fertilizing them in a laboratory, and implanting a fertilized egg inside the womb.
The bill's sponsor, Rep. Dan Ruby, a Republican, sent an e-mail message to Democratic senators before Friday's vote, offering to write letters to the editor to vouch for their anti-abortion credentials if they backed the legislation.
"I will demonstrate my belief that this issue is more important than partisan politics," Ruby wrote.