Confusion over how pregnancy dates are measured is widespread – and makes for uninformed debate over abortion limits

(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.)

Laurel Elder, Hartwick College; Mary-Kate Lizotte, Augusta University, and Steven Greene, North Carolina State University

(THE CONVERSATION) Most Americans don’t know two key facts about pregnancy, including how they are dated and how long a trimester is – and this could matter, as a growing number of states place restrictions on abortion.

Florida enacted a new law on May 1, 2024, that bans abortions after six weeks of pregnancy, with a few exceptions – including documented rape, incest and to save the life of the mother.

Florida joins the majority of Southern states that now have complete bans or highly restrictive abortion laws, enacted since the Supreme Court overturned the federal right to get an abortion in June 2022. Many of the restrictive laws ban abortion after a set number of weeks.

Florida Republicans supporting the bill have labeled it a reasonable compromise between a full abortion ban and few abortion...