Companies like Disney, WarnerMedia and Netflix have also warned they will reconsider doing business in the state should the law be enacted.
A 2005 survey, which backs abortion rights, found about 1 per cent of women said they had abortions because of rape or incest.
Speaking to a Vatican-sponsored anti-abortion conference, Francis said the opposition to abortion isn't a religious issue but a human one.
Under the law that comes into force August 28, doctors who violate the eight-week cutoff could face five to 15 years in prison.
Women who obtained pills online described desperation at being unable to access affordable medical services locally, with some saying they had considered extreme measures to end their pregnancies.
Women's reproductive rights defenders will gather to denounce the "Alabama Human Life Protection Act," or HB314, which virtually outlaws terminations.
Mace is against abortion in most cases and supported the fetal heartbeat bill as long as it contained the exception for rape and incest.
The Missouri legislation comes after Alabama's governor signed a bill Wednesday making performing an abortion a felony in nearly all cases.
Planned Parenthood Action Fund President Leana Wen said in a statement that enacting the measure would be disastrous.
Anti-abortion campaigners have successfully enacted a ban on all or most abortions in Arkansas, Kentucky, Mississippi, North Dakota, Ohio and Georgia.
If a new Mississippi law survives a court challenge, it will be nearly impossible for most pregnant women to get an abortion there.