Nearly a quarter of people seeking an abortion in the United States were unable to get one due to bans that took effect after the Supreme Court’s Dobbs decision, researchers estimate. In the first half of 2023, states with abortion bans had an average fertility rate that was 2.3% higher than states where abortion was not restricted, according to the analysis – leading to about 32,000 more births than expected.

The findings are based on preliminary births data from the US Centers for Disease Control and Prevention. The research has not yet been peer-reviewed but experts say the data paints a clear picture about the direct impact of abortion restrictions.

“It’s an assault on reproductive autonomy,” said Alison Gemmill, an assistant professor at the Johns Hopkins Bloomberg School of Public Health. She was not involved in the new analysis, but has published research on the effect that a strict abortion law had on births in Texas.

“We don’t always detect signals in these population aggregates because there’s a lot of variation when you group everybody together. The fact that there is a signal at the population level means that something’s really going on. It’s pretty strong evidence.”