Fetal viability is at the center of Mississippi abortion case. Here’s why.

Conservative justices questioned that legal and scientific framework in Dobbs v. Jackson Women’s Health Organization, a case that could change abortion rights

The Jackson Women's Health Organization clinic is challenging Mississippi's 15-week abortion ban. (Rogelio V. Solis/AP)

When the U.S. Supreme Court agreed to hear arguments over Mississippi’s 15-week abortion ban in Dobbs v. Jackson Women’s Health Organization, it focused on a single question: Whether “fetal viability” is legitimate criteria for how far states may go to restrict women’s access to abortion.

In the 1973 Roe v. Wade decision, the court majority held that a women’s right to choose to end a pregnancy was protected by the Constitution, but that states could limit that right after the second trimester or 28 weeks, when a fetus might survive outside the womb. In 1992′s Planned Parenthood v. Casey, the court affirmed that right but opted for a framework based on fetal viability rather than trimesters.

Here’s why that’s important and what it means for the case currently before the court, and more broadly, for abortion rights in the United States.

Roe v. Wade and abortion access in America

Roe v. Wade overturned: The Supreme Court has struck down Roe v. Wade, which for nearly 50 years has protected the right to abortion. Read the full decision here.

What happens next?: The legality of abortion will be left to individual states. That likely will mean 52 percent of women of childbearing age would face new abortion limits. Thirteen states with “trigger bans” will ban abortion within 30 days. Several other states where recent antiabortion legislation has been blocked by the courts are expected to act next.

State legislation: As Republican-led states move to restrict abortion, The Post is tracking legislation across the country on 15-week bans, Texas-style bans, trigger laws and abortion pill bans, as well as Democratic-dominated states that are moving to protect abortion rights enshrined in Roe v. Wade.

How our readers feel: In the hours that followed the ruling in Dobbs v. Jackson Women’s Health Organization, Washington Post readers responded in droves to a callout asking how they felt — and why.