The risk had not been substantiated by robust scientific evidence<\/a> when Trump issued the warning. Now, a group of researchers have responded with what may be the most thorough analysis yet of the existing science on the topic.<\/p>\n Their review, published Friday in the medical journal The Lancet Obstetrics, Gynaecology, & Women\u2019s Health<\/a>, found no link between acetaminophen \u2014 the active ingredient in Tylenol, also known as paracetamol \u2014 taken during pregnancy and autism, attention-deficit\/hyperactivity disorder or intellectual disability. <\/p>\n The authors said they undertook the research, in part, to clear up confusion after Trump\u2019s statements, since an untreated fever can pose health risks to a mother and baby.<\/p>\n \u201cAfter this declaration, there were a lot of mothers who actually were scared to take paracetamol,\u201d said Dr. Francesco D\u2019Antonio, one of the paper\u2019s authors and a professor of fetal medicine at the University of Chieti in Italy. \u201cThe day after this declaration, actually, we had a massive increase in phone calls and emails from women.\u201d<\/p>\n The report\u2019s main takeaway is that acetaminophen is safe during pregnancy, according to Dr. Asma Khalil, another one of the paper\u2019s authors and a consultant obstetrician and fetal medicine specialist at St. George\u2019s Hospital in London. <\/p>\n \u201cIt remains to be the first line treatment that we would recommend if the pregnant women have pain or fever,\u201d she said on a call with reporters. <\/p>\n In a press release, The Lancet referred to the paper as a \u201cgold-standard evidence review.\u201d <\/p>\n The description echoes language from members of the Trump administration. During the September announcement, Kennedy said the National Institutes of Health would unleash \u201cunbiased, depoliticized, gold standard scientific research and academic freedom\u201d in its investigation of autism\u2019s causes.<\/p>\n Four researchers who weren\u2019t involved in the new paper praised its rigor.<\/p>\n \u201cI don\u2019t think there\u2019s a better way to analyze the data than this Lancet paper does,\u201d said David Mandell, a psychiatry professor at the University of Pennsylvania.<\/p>\n The seven-person team behind the new paper, from the U.K., Italy and Sweden, used three methods to evaluate studies published through September. <\/p>\n First, they excluded studies that did not compare pregnancies in which Tylenol had been used to those without it, as well as research that did not disclose pregnant women\u2019s health histories or which medications they were taking. They also did not include studies that asked women to self-report whether they had taken Tylenol and whether their child had autism. Instead, the researchers relied only on studies that used medical records or questionnaires administered or reviewed by a health care provider. Out of thousands of studies, 43 made the cut.<\/p>\n Next, the researchers rated the studies based on their quality and whether any factors may have biased the results. They excluded poor quality ones, such as those that didn\u2019t follow study participants for very long or didn\u2019t clearly define the health outcomes. <\/p>\n Finally, they did a closer assessment of the two most robust studies on Tylenol use and autism, which each compared large groups of siblings \u2014 one that had been exposed to Tylenol in utero and one that had not. The siblings shared genetics and were raised in roughly the same environment, with the same socioeconomic and educational backgrounds, so the researchers could presume that those factors did not influence the study results. <\/p>\n All three methods led to the same conclusion: There was no link between Tylenol use in pregnancy and neurodevelopmental disorders.<\/p>\n \u201cNo matter which way they analyze them, they find that acetaminophen doesn\u2019t cause ADHD or autism or intellectual disability,\u201d Mandell said. <\/p>\n When asked about the findings, an official from the Health and Human Services Department said the analysis does not resolve the question of whether Tylenol use is linked to autism. The official alleged that the paper engineers a finding by excluding evidence and designing a study with a bias toward showing no association. <\/p>\n \u201cAccording to HHS, many experts have expressed concern of the use of acetaminophen during pregnancy,\u201d said Andrew Nixon, a spokesperson for the department.<\/p>\n Nixon named, in particular, Dr. Andrea Baccarelli, dean of faculty at the Harvard T.H. Chan School of Public Health, whose review last year<\/a>, published in the journal Environmental Health, found an association between autism and Tylenol use in pregnancy. The Trump administration cited the research as evidence of Tylenol\u2019s purported risks. Baccarelli did not respond to a request for comment. <\/p>\n Khalil said that Baccarelli\u2019s review and other small studies that have found such associations probably didn\u2019t do enough to exclude confounding factors.<\/p>\n Mandell also said Baccarelli\u2019s review did not comb through nearly as many papers as the new analysis did.<\/p>\n \u201cAt the very least, it suggests a sloppy search,\u201d he said.<\/p>\n In the months since his initial statements about Tylenol, Trump has doubled down, writing on Truth Social<\/a> earlier this month: \u201cPregnant Women, DON\u2019T USE TYLENOL UNLESS ABSOLUTELY NECESSARY.\u201d<\/p>\n![\"Health](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2026\/01\/250923-donald-trump-robert-kennedy-mn-0910-6e7c2f.jpg\")
Health and Human Services Secretary Robert F. Kennedy Jr. speaks to President Donald Trump during a news conference on Sept. 22 at the White House.Tom Brenner \/ The Washington Post via Getty Images file<\/p>\n