HELENA — A bill that would ask voters to decide if Montana should declare a compelling state interest in fetuses fell 21 votes short of passing in a preliminary vote in the House on Thursday.

Senate Bill 274, by Sen. Dan McGee, R-Laurel, seeks to amend the state' s constitutional right to privacy and declare a compelling state interest in fetuses. Fifty-one of the 100 representatives voted for it Thursday, but a simple majority vote is not enough to alter the state's constitution.

SB274 passed out of the Senate with 28 votes in February and, therefore, needs 72 votes in the House to pass out of the Legislature and go before voters. A proposed constitutional amendment requires the backing of at least 100 of the 150 legislators.

The measure would pave the way for the state Supreme Court to grant parents the right to know if their minor child is having an abortion, to ban late-term abortions and to give those seeking an abortion a full understanding of the procedure, according to proponents.

Opponents said McGee's bill would jeopardize the privacy rights of all pregnant women.

Rep. Christine Kaufmann, D-Helena, said the consequences of the bill are far-reaching. She said the bill could allow the state to prosecute women for exposing fetuses to secondhand smoke, to criminally charge them if something went wrong during a home birth and possibly to charge a pregnant woman with homicide if her fetus died as a result of a car accident.

Rep. Larry Jent, D-Bozeman, a lawyer, said the proposed constitutional amendment would never withstand a court challenge.

Rep. Jeff Laszloffy, R-Laurel, who sponsored the bill for McGee in the House, said the bill deals with the reality of abortion but doesn't try to restrict the procedure.

"We're not seeking to overturn abortion," he said. "Roe v. Wade is the law of the land."