Alva Review-Courier -

NASHVILLE, Tenn. (AP) — The abortion bans taking effect after the nation's highest court overturned Roe v. Wade vary greatly in how they define when a pregnancy can be ended.

Some laws prohibit abortion at the point of the "first detectable heartbeat" while others restrict abortion at 15, 22 or 24 weeks of pregnancy. This means determining how far along someone is in pregnancy — gestational age — has become more important, because there is a smaller window of time to secure the procedure in about half of the states in the U.S.

Here's a look at how gestational age is determined and how states u...