Texas passes one of the most restrictive abortion laws in the U.S.

Republican Texas Governor Greg Abbott on Wednesday signed into law a "fetal heartbeat" abortion bill that bans abortion after about six weeks of pregnancy and grants citizens the right to sue doctors who perform the procedure past that point.

The new law is part of a wave of similar "heartbeat" abortion bans passed in Republican-led states. Lawmakers who support such legislation have said it is intended to lead to an overturn of Roe v. Wade, the U.S. Supreme Court's 1973 landmark ruling that guaranteed a woman's right to end her pregnancy.

The high court this week opened the door for such an overturn, or at least a narrowing, of Roe v. Wade by agreeing to review Mississippi's bid to ban abortions after 15 weeks.

"Our creator endowed us with the right to life, and yet millions of children lose their right to life every year because of abortion," Abbott said before signing the bill, in a video posted on Facebook. "In Texas, we work to save those lives."

The Texas law bans abortion once the rhythmic contracting of fetal cardiac tissue can be detected, often at six weeks — sometimes before a woman realizes she is pregnant. The measure makes an exception for abortions in cases of medical emergencies.

One of several states to recently pass abortion laws

A fetus that is viable outside the womb, at around 24 weeks into a pregnancy, is widely considered the threshold at which abortion can be prohibited in the United States.

Nearly a dozen states have passed similar "heartbeat" abortion bans, according to reproductive health research organization the Guttmacher Institute, but none have taken effect due to legal challenges.

Abortion is one of the most divisive issues in the United States, with opponents citing religious belief to declare it immoral, and abortion rights advocates prioritizing women's autonomy.

"It is appalling that in defiance of public opinion and public health, state politicians remain committed to controlling our bodies," Planned Parenthood Action Fund president Alexis McGill Johnson said in a statement on Wednesday.

Kimberlyn Schwartz, spokesperson for the anti-abortion group Texas Right to Life, called the law "a vital step in the road to abolishing all abortions in Texas."

Texas's law, which will take effect in September if it is not overturned in court, allows citizens to sue anyone who "knowingly engages in conduct that aids or abets the performance or inducement of an abortion, including paying for or reimbursing the costs of an abortion through insurance or otherwise," if the abortion violates the provisions of the law.

"This bill essentially opens the floodgates to allow anyone who is hostile to abortion to sue doctors and clinics," the Center for Reproductive Rights said in a statement, vowing to "pursue all legal options" to stop the law from taking effect.

In an open letter earlier this month, some 200 Texas physicians said they were worried the law would expose doctors to the risk of "frivolous lawsuits that threaten our ability to provide health care."

"As licensed physicians in Texas, we implore you to not weaponize the judicial branch against us to make a political point," the letter said.