Mississippi Gov. Phil Bryant signed a bill Thursday that bans abortions once a fetal heartbeat is detected.
The bill would prohibit elective abortions as early as six weeks into pregnancy. Critics have said most women don't even know they're pregnant at that time.
Other states have passed similar bills before, but many were found unconstitutional. Lawmakers in Ohio, Tennessee and Georgia are working to pass similar bills right now.
The nonprofit Center for Reproductive Rights has already said it's taking Mississippi to court.
In a statement, an attorney for the center called the ban "one of the most restrictive abortion bans signed into law." She also said the state's lawmakers "are determined to rob Mississippians of the right to abortion, and they are doing it at the expense of women's health and taxpayer money. This ban — just like the 15 week ban the Governor signed a year ago — is cruel and clearly unconstitutional."