What Six-Week Abortion Bans Really Mean

The U.S. Supreme Court is reentering the abortion debate this fall, hearing arguments over the constitutionality of a Mississippi law banning the procedure after 15 weeks of pregnancy. Though observers expect the court’s conservative majority to issue a ruling that could potentially scale back or even eliminate Roe v. Wade, the nation’s decades-old abortion rights guarantee, some states are moving forward with even tighter restrictions.

On September 1, a Texas law passed in May that effectively bans abortion after six weeks went into effect. The law directly violates Roe v. Wade, which guarantees the right to terminate a pregnancy up until the fetus can independently live outside the womb, usually around 23 weeks of pregnancy. Experts explain just how restrictive these laws are, who would be most affected, and why, legally, their future is still unclear.

The Pregnancy Clock and Detection Challenges

A six-week ban on abortion would be much more restrictive than it sounds, acting as a de facto ban for many. For many people, six weeks is early enough that they haven’t actually realized they are pregnant. The pregnancy clock starts by counting back to the person’s last menstrual period. A typical menstrual cycle is 28 days — four weeks — but many people have irregular periods, which can be brought on or exacerbated by stress or fatigue. Those factors mean someone might not realize they are pregnant until 30 or 40 days, which is just shy of the six-week deadline.

“To call it a six-week ban — it’s really a two-week window at best,” said Katherine Kraschel, a lecturer at Yale Law School and expert on reproductive health policy. Some pregnancy tests can detect a positive before a missed period, but that isn’t the norm. Six weeks is early enough that many people aren’t likely to realize they are pregnant, let alone decide whether they want to get an abortion.

Data on Abortion Timing

Most abortions occur in the first trimester, and don’t require surgery. According to data from the Centers for Disease Control and Prevention for 2018, the timing of procedures is as follows:

• At or before six weeks: About 36 percent of abortions — just over a third.
• At or before nine weeks: Almost 78 percent of abortions.
• At or by the 13th week: More than 92 percent of abortions.

That indicates that the majority of abortions occur between six and 13 weeks of gestation. A six-week ban would prohibit the procedure at a point when almost two-thirds of people who would have sought an abortion haven’t yet terminated their pregnancy, according to those numbers.

Impact on Unplanned Pregnancies

No organization collects data tracking when most people discover they have conceived. But about half of all pregnancies in the United States are unplanned. In those cases especially, people often don’t realize they are pregnant until they have missed at least one menstrual cycle.

“Some people have thought about abortion before, but not everybody,” said Elizabeth Nash, who tracks state policy for the nonpartisan Guttmacher Institute. “That means they need some time to figure out what they want to do — and these are the people who know they’re pregnant.”