This article is republished from: conversation Under Creative Commons License. Read the original article, “Confusion over how to date pregnancy is widespread, leading to ignorant arguments about abortion restrictions.”
By Laura Elder, Mary-Kate Resort, and Stephen Green
Most Americans don't know two key facts about pregnancy, including how to count the days and how long your pregnancy lasts. This could be problematic as more and more states are restricting abortion.
Florida enacted a new law on May 1 that bans abortion after six weeks of pregnancy, with a few exceptions for rape, incest and to save the pregnant woman's life.
Florida joins most Southern states with outright bans or very restrictive abortion laws enacted after the Supreme Court overturned the federal right to abortion in June 2022. Many restrictive laws prohibit abortion after a set number of weeks.
Anti-abortion rights groups such as Susan B. Anthony Pro-Life America have called the six-week abortion ban the gold standard for abortion policy. Florida Republicans supporting the bill characterized it as a reasonable compromise between an outright abortion ban and limiting abortions to a limited number of cases.
Some obstetricians and gynecologists explained that many people don't even know they are pregnant at six weeks. Studies show that on average, people find out they are pregnant after five and a half weeks. About 23% do not find out until after the 7th week of pregnancy.
So do Americans, including those who enacted the six-week ban, actually understand how timing or dates of pregnancy work?
We are scholars in the fields of political science, gender, and public opinion, and we are working on a book about public opinion on abortion following the Supreme Court's June 2022 ruling to revoke federal abortion rights.
How does pregnancy proceed?
To gain insight into this issue, we developed several pregnancy questions and included them in a research survey conducted in late September 2023. The survey involved 1,356 respondents, broadly representative of the U.S. population. The average age of respondents was 46 years. About 49% of them were male, 70% were white, and 29% were college graduates. Meanwhile, 43% of them were Democrats and 38% were Republicans.
The first question asked respondents how they date their pregnancy. The answer is that the first day of your last menstrual period (often 2 to 3 weeks before conception) is used to determine the date of conception.
The second question asked about the third trimester. Many Americans are familiar with the term third trimester, and public opinion polls consistently show that Americans find abortion most acceptable in the first trimester of pregnancy. We asked Americans if they knew roughly how many weeks a trimester is. The correct answer is 13.
Americans' Pregnancy Knowledge
We found that only one-third of respondents knew the date of conception. The majority (about 60%) mistakenly believed that pregnancy occurred from the time of conception or a few weeks after their last sexual intercourse. Less than a quarter of respondents answered both pregnancy knowledge questions correctly.
In the survey, we also asked respondents whether they supported a six-week abortion ban. Similar to other national surveys, it found that most Americans oppose strict abortion restrictions. Only 35% support a six-week ban.
Importantly, those who support a six-week abortion ban are significantly less likely than others to have an accurate understanding of the timing of pregnancy. The statistically significant relationship between low levels of knowledge about the timing of pregnancy and support for a six-week abortion ban holds even in analyzes that control for potentially confounding variables.
Some anti-abortion lawmakers have previously shown ignorance about pregnancy.
For example, there is a long history of some anti-abortion politicians inaccurately saying that it is extremely rare for someone who has been raped to become pregnant. Our research shows that many of those who oppose abortion lack knowledge about the basics of pregnancy.
gender gap
Not surprisingly, the women in this survey knew more about pregnancy than the men. For example, when asked how to date a pregnancy, 43% of women answered correctly, compared to only 23% of men. As mentioned above, the majority of Americans incorrectly believe that pregnancy begins at conception, but far more men than women believe this to be true.
This finding is especially important considering the gender breakdown of Florida lawmakers who approved the six-week ban. We don't have data on the pregnancy knowledge of those legislators, but we do know that those who voted for the ban were overwhelmingly men.
Florida's six-week ban will make it much more difficult for anyone there to obtain an abortion, and will also affect people in neighboring states who want or need an abortion. In 2023, Florida had the closest abortion clinic for 6.4 million women living in the South. In 2023, about 7,700 women traveled to Florida to obtain abortions from other southern states, where abortion is now largely banned.
Overall, our findings raise serious questions about whether Americans without medical training, like those in our state legislatures, have the knowledge necessary to regulate access to abortion.