Fact-Checking The Guardian: Will Most Pregnant Women and Babies Who Get Bird Flu Die?

An article in The Guardian misrepresented the findings of a new study on pregnant women and bird flu, according to scientists who reviewed the study for The Defender.

by Brenda Baletti, Ph.D.

An article published Thursday in The Guardian — under the headline “Most pregnant women and unborn babies who contract bird flu will die, study finds” — misrepresented the study’s findings, according to scientists who reviewed the study for The Defender.

As public health officials ramp up panic around a possible bird flu pandemic, The Guardian also reported that a “severe strain of bird flu known as highly pathogenic avian influenza A (H5N1) is spreading globally.”

However, the news outlet added the caveat that human infections are rare, limited to people who work in close contact with animals and there is no evidence of transmission between humans.

That information aligns with the latest update on H5N1 from the Centers for Disease Control and Prevention (CDC), which states the “current public health risk is low.”

How did The Guardian come up with its headline?

Let’s take a closer look at the study — “Systematic Review of Avian Influenza Virus Infection and Outcomes during Pregnancy” — published in the January 2025 edition of the CDC’s Emerging Infectious Diseases journal.

Lead author Rachael Purcell said that while many people who became infected with bird flu were “completely fine, we wanted to look at what is known about what happens to pregnant women,” The Guardian reported.

To accomplish this, the authors assessed over 1,600 studies on bird flu. Purcell and her team identified only eight studies involving a total of 30 pregnant women who contracted various strains of bird flu. None of those were the same H5N1 strains circulating currently.

The researchers’ analysis of the eight studies and 30 pregnant women found high mortality rates — again, from older bird flu strains, not those in circulation now.

They concluded that the mortality rates indicated that “awareness of the vulnerability of pregnant women to a new pandemic is needed.” They didn’t claim, as The Guardian did, that most pregnant women and unborn babies who get bird flu will die.

The authors said their findings support the case that a “paradigm shift” is needed, where pregnant women are included early in clinical trials for vaccines produced as part of “pandemic preparedness.” Typically, pregnant women are excluded from such studies due to safety concerns, until a drug has proven safe in a healthy population.

Critics of the study told The Defender there were problems with the study’s methodology. They also said the authors’ recommendation that pregnant women be included early in trials for experimental vaccines is dangerous.

“This is a terrible idea, because most drugs and vaccines subjected to clinical trials fail, putting fetus and pregnant women at high risk for no benefit,” internist and bioweapons expert Dr. Meryl Nass said.

Study’s ‘data have no bearing on today’

Purcell and her team searched 1,602 research papers on bird flu to find cases in pregnant women. They found only seven case reports and one retrospective study that had data on pregnant women. Some of those had to be eliminated because they reported on the same cases.

The researchers’ final review included data on 30 pregnant women diagnosed with different types of avian influenza virus infection during pregnancy. Most women were from China and contracted bird flu working in poultry factories or at live poultry markets.

The review found that 90% of women infected with bird flu during pregnancy died, and almost all of their babies died with them. Of the babies who survived, most were born prematurely.

Nass said it was notable that after reviewing 1,602 studies the authors found so few studies that fit their criteria. “From this meager amount of data the authors derived mortality rates in pregnancy.”

Children’s Health Defense (CHD) Senior Research Scientist Karl Jablonowski agreed. “The idea that they would start with 1,600 papers and whittle that down to eight is introducing a huge potential bias.”

Jablonowski said the authors also introduced bias based on the types of studies they used. “We’re seeing the aggregation of the worst possible outcomes in the published literature, in order to draw conclusions about mortality.”

Jablonowski said that case reports and case studies focus on bad outcomes. “The worse the outcome, the greater the published documentation,” he said. “Is 27 maternal deaths of the 30 infected an accurate description of outcome — or an aberration of compounding biases? This study was not designed to answer that question.”

He said it was impossible to independently analyze the single Chinese retrospective study the authors rely on because the paper does not include the data. “I think we’re surrounded by such a large cloud of bias that any estimate of the true fatality rate would be so skewed that it’s irresponsible to make the estimate.”

Nass said the authors included H5N2 infections and other strains of bird flu that “are not currently causing problems anywhere in the world.”

Grouping different strains of flu in the analysis “makes no sense” she said, “because each will have a different mortality rate, severity and ability to infect humans. Each will also require a unique vaccine.”

“These data have no bearing on today,” Nass added, “because bird flu cases affecting chickens, cows and the Americans who work with them are mild due to a mutated strain. The strains affecting the pregnant women in the study have disappeared.”

Even experts interviewed by The Guardian to endorse the paper, like infectious diseases specialist and associate professor Sanjaya Senanayake at the Australian National University, were tepid in their support.

Senanayake told The Guardian the sample size was small and the severe outcomes in the paper couldn’t be generalized to “the developed world with better resourced healthcare settings.”

However, he said he thought the findings of the study were “likely to be real.”

More vaccines for pregnant women?

The bulk of the paper argued that pregnant women should be included in clinical trials for new vaccines for possible future pandemics.

Purcell told The Guardian the study outcomes highlighted that “whilst the risk of avian influenza becoming the next human pandemic is thought to be low, it’s really important to think about vulnerable populations and how we might protect them and include them in vaccination programs.”

“Despite being a high-risk population, pregnant women are often excluded from vaccine trials, from priority access to therapeutics, and experience delayed entry into public health vaccination programs,” she said.

But Nass argued that “we know” pregnant women and their fetuses are more susceptible to the adverse effects of drugs and vaccines. “They should only be included in clinical trials for drugs or vaccines that are sure to be, or already, licensed.”

Jablonowski said that “ethically, it’s a huge issue to push a vaccine that hasn’t even been proven safe in the healthy portion of the general population and then apply that vaccine to an undeniably vulnerable part of the population, which is not only a pregnant mother, but her unborn child.”

‘Fear porn’ resting ‘on a very flimsy foundation’

Nass said the authors of the study exaggerated even their most basic claims. The World Health Organization reports 13 cases of H5N1 bird flu globally in 2024 outside the U.S., and the CDC reports 61 cases within the U.S.

“While the authors claim cases are increasing globally, they are increasing very very slowly and are not a threat to people who are not directly involved with affected cows or birds,” Nass said.

Nass added:

“According to the authors, public health officials should be proactive and plan for pandemics before they occur. However this claim is a pipe dream, because until they occur you do not know what infection will turn into a pandemic. That is, unless you are deliberately spreading it.”

Only one person in the U.S. has contracted a wild bird flu strain that might be more virulent, she said. “We cannot vaccinate against wild bird strains that are extremely unlikely to affect humans.”

CHD Chief Scientific Officer Brian Hooker called the paper “fear porn” resting “on a very flimsy foundation in the original paper,” which has only 30 pregnancies with three very different viruses and the majority of the cases in China.

Extrapolating this data to Australia, where the authors live, or the U.S. “is preposterous, especially given the current circulating strains specifically in the U.S. causing pink eye.” In the one severe case reported, the sick person had other underlying conditions, he said.