Study: Maternal mortality statistics distorted by COVID, did not decrease until end of Roe v. Wade case

Federal statistics suggesting that maternal mortality rates dropped sharply after the Roe v. Wade ruling was overturned are “highly misleading” and are being misinterpreted by anti-abortion activists, according to a new study published this week in the journal. JAMA network opened.

“We want to set the record straight,” said co-author Amanda Stevenson, assistant professor of sociology at the University of Colorado Boulder. “Maternal mortality has actually not decreased since the Dobbs decision.”

The paper highlights how statistical artifacts from the COVID-19 pandemic can distort death data and questions the way the federal government presents statistics on its website. The authors now urge policymakers to exercise “extreme caution” when using such figures to inform policy.

“We have seen a case where published data have been used to make claims about abortion and pregnancy-related deaths that are simply not true,” said co-author Leslie Root, assistant professor at the Institute of Behavioral Science. “This paper is about correcting that.”

What the numbers really say

Previous research by Stevenson and others predicted that abortion bans would ultimately increase maternal mortality – defined by the World Health Organization as any death during pregnancy or within 42 days of terminating a pregnancy – because abortion is exponentially safer than maintaining the pregnancy.

However, published data from the National Center for Health Statistics appear to show a steep decline in maternal mortality in the months following the June 2022 Dobbs decision, a Supreme Court ruling that ended the constitutional right to abortion and led to bans in 14 states.

Abortion opponents have cited these data in their efforts to expand abortion restrictions, including in a brief submitted to the U.S. Supreme Court in June in the Emergency Medical Treatment and Active Labor Act (EMTALA) case.

As social demographers, Stevenson and Root set about taking a closer look at the numbers.

Stevenson explains that current maternal mortality statistics are in high demand and there are numerous ways to obtain them: Raw, real-time monthly numbers are available upon request, but are very preliminary and subject to statistical noise or outside variables. As a result, the NCHS only displays “12-month totals” on its official website, which summarize all deaths over the past 11 months and the current month.

Root and Stevenson analyzed the Centers for Disease Control's monthly maternal mortality figures from 2018 to 2023, as well as COVID-19 deaths among women of childbearing age from January 2020 to September 2023.

They then compared the monthly figures with the totals for the last 12 months.

They found that a total of 4,802 pregnant people died from January 2018 to September 2023. From September 2022 to February 2023, shortly after the Dobbs ruling, the “twelve-month totals” actually showed a significant decline. However, the monthly numbers remained stable.

They also found that exactly one year before the apparent plunge in maternal mortality shown on the NCHS website, delta and omicron waves were rising, with Covid-related deaths among pregnant women increasing and pandemic-related restrictions making it harder for them to get medical care.

For example, based on NCHS 12-month totals, the maternal mortality rate appeared to decline by 125 deaths between August 2022 and September 2022 alone (two months after Dobbs). But 93 of the deaths reported in August 2022 actually occurred 11 months earlier, in September 2021, at the height of the pandemic. Similarly high proportions of the declines during the September 2022 to February 2023 period can be explained by deaths that occurred 12 months earlier.

After the months of COVID surge were removed from the 12-month results, maternal deaths decreased.

“We conclude that the rapid decline in numbers at the end of the Dobbs 12-month period was actually due to events in 2021, particularly the shock to maternal mortality during the delta and omicron waves of the pandemic,” Stevenson said.

In an invited commentary published in the same journal, Dr. Paula Lantz of the University of Michigan's Ford School of Public Policy praised the authors for meeting a “urgent need for objective, high-quality research to evaluate abortion policy.”

“The results clearly demonstrate that the observed decline in maternal mortality following the 2022 ruling in Dobbs v. Jackson Women's Health is the result of a resolution of the COVID-19 mortality shock and is not due to the passage of new restrictive abortion laws by state legislatures,” she wrote.

Stevenson and Root point out that similar statistical artifacts from the pandemic could also distort other publicly available mortality data. They warn policymakers to be “extremely cautious” when making decisions based on “seemingly reasonable but highly misleading” data.