In practice, the number is small. Approximately 9,090 women in the United States had abortions after their 21st week of pregnancy in 2012. That’s 1.3 percent of all abortions, and roughly 0.14 percent of all pregnancies, based on the 2010 U.S. pregnancy rate.
Yet states keep creating legislation on this issue, proposing abortion bans at 24 or 22 weeks. Many—like South Carolina, where one such bill was signed into law last week—provide exceptions for medical emergencies or fetal anomalies. In fact, many of the women who seek abortions at this stage in their pregnancies do so for health reasons, so these bans affect only a subset of those 9,090 women. Moreover, in states like South Carolina, it can be difficult or even impossible to find an abortion provider who will perform the procedure at that stage. The Planned Parenthood in Columbia, for example, will only provide abortions up until 13 weeks and 6 days into the pregnancy.
So it might seem surprising that these laws, which affect very few women, keep getting pushed and passed. But even though laws like these are often contested through protests, lawsuits, or both, they’re not that different from the abortion prohibitions in a vast majority of states around the country. There’s a kind of national mean on abortion limits in the United States—a significant majority of states, from the most conservative to the most liberal, ban the procedure somewhere between 22 weeks and viability, which “most obstetrician-gynecologists understand ... as occurring near 24 weeks gestation,” according to American Congress of Obstetricians and Gynecologists. There are only seven states—Alaska, Colorado, New Hampshire, New Jersey, New Mexico, Oregon, and Vermont—that don’t limit abortion by gestational age at all. And only three let women wait until their third trimester begins, around 28 weeks. State by state, a nearly uniform consensus has emerged in America: After roughly two dozen weeks, women should not be able to get an abortion for non-medical reasons.