More than 600 reproductive rights marches are set for Saturday. Here's what you need to know

Women and allies will gather at more than 600 marches across the United States on Saturday in support of reproductive rights, with the largest rally expected in the nation's capital, according to organizers.

These "Rally for Abortion Justice" marches come as the most restrictive anti-abortion bill yet went into effect in Texas last month, which banned abortions after six weeks -- before many women know they have conceived -- with no exceptions for rape or incest.

"We don't say this lightly: we're at grave risk of losing our reproductive freedoms," The Women's March account tweeted. "All of us need to fight back. That's why on October 2, we're marching in every state."