Voters narrowly approved Amendment 3 on Nov. 5, which adds a “fundamental right to reproductive freedom” to the state constitution, threatening to undo decades of pro-life gains.

Amendment 3 places language in the Missouri Constitution legalizing abortion up to fetal viability, which is usually around 24 weeks. Now that the amendment passed, abortion rights proponents plan to file lawsuits to strike down the state’s near-total ban.

When it goes into effect in December, Amendment 3 will protect abortion up to what’s known as fetal viability — which is about 24 weeks of pregnancy.