Three Republican and one Democratic Mississippi legislator have authored a proposed amendment to the state's constitution that would defined "a person" as beginning at the moment of conception, according to Talking Points Memo.

The Right to Life Amendment of 2012 is intended to ban abortion and to set up a legal challenge to Roe v. Wade, which upheld a woman’s right to terminate her pregnancy until the fetus is viable outside the womb.

A similar constitutional amendment was rejected by more than 55 percent of Mississippi voters last November. Critics of the amendment said it would not only outlaw abortion, it would also affect common birth control methods, the treatment of ectopic pregnancy, in vitro fertilization treatment, and stem cell research.

The proposed amendment introduced to the Mississippi’s House of Representatives this week, however, addresses those concerns. It states that “certain activities that are not affected or prohibited by this section, including contraception or birth control not killing a person, in vitro fertilization or other methods of reproduction, medical treatment intended to preserve life, or miscarriage.”

Republicans in state legislatures across the country have pushed for tighter restrictions on abortions, such as requiring ultrasounds before a woman can terminate her pregnancy or mandating a 24-hour waiting period.

Thanks to their electoral victories in 2010, conservatives lawmakers successfully enacted 92 measures aimed at restricting abortion in 2011, according to the Guttmacher Institute.