For years, research have urged that a mom’s health throughout pregnancy might affect her youngster’s chance of growing autism. However, a groundbreaking new research, leveraging Denmark’s in depth medical data, reveals a totally different story.
Researchers discovered that just about all beforehand suspected maternal situations weren’t really inflicting autism however had been as an alternative linked via genetics or environmental components. The solely constant associations with autism got here from fetal problems, which scientists now imagine are early indicators of autism quite than its trigger.
Rethinking Autism Risk Factors
Many research have urged a link between a mom’s health throughout pregnancy and her youngster’s danger of autism. However, a new research finds that just about all of those connections could be defined by different components, reminiscent of genetics, environmental exposures like air pollution, and entry to healthcare.
Conducted by researchers at NYU Langone Health, the research discovered that the one pregnancy-related situations actually related to autism had been problems affecting the fetus. This means that these problems will not be causes of autism however quite early indicators of it.
No Evidence That Maternal Health Causes Autism
“Our study shows that there is no convincing evidence that any of these other diagnoses in the mother can cause autism,” mentioned research senior writer Magdalena Janecka, PhD, an affiliate professor within the Department of Child and Adolescent Psychiatry and within the Department of Population Health, at NYU Grossman School of Medicine.
Publishing within the journal Nature Medicine on-line Jan. 31, the brand new research included an evaluation of
the medical histories of greater than 1.1 million pregnancies (amongst 600,000 moms) from a nationwide registry in Denmark. Unlike medical data within the United States, which are sometimes scattered amongst many alternative medical suppliers a person sees throughout their lifetime, in Denmark all of a person’s health data are consolidated below a single government-issued quantity, which enabled researchers to verify every lady for greater than 1,700 distinct diagnoses as outlined by worldwide requirements, generally known as ICD-10 codes. From these, researchers targeted their evaluation on these identified in at the least 0.1% of pregnancies (236 diagnoses).
“We believe our study is the first to comprehensively examine the entire medical history of the mother and explore a wide range of possible associations, controlling for multiple concurrent conditions and confounding factors,” mentioned research lead writer Vahe Khachadourian, MD, PhD, MPH, a analysis assistant professor within the Department of Child and Adolescent Psychiatry at NYU Grossman School of Medicine.
Denmark has strict safeguards in place to stop misuse of the registry information, says Janecka, because it accommodates private data. However, due to the individual-specific data, the researchers had been capable of cross-check each analysis a lady had had together with her youngsters’s danger of autism.
Untangling the Genetic and Environmental Puzzle
For the research, the researchers corrected for components that might confound, or provide another clarification for, the link between the analysis a lady obtained and a youngster’s autism analysis. These components embody sociodemographic standing and the mom’s age throughout pregnancy, since youngsters of older moms usually tend to be identified with autism, and their moms are additionally extra prone to obtain sure diagnoses, reminiscent of hypertension, than their youthful counterparts.
After accounting for these confounding components, in addition to for concurrent diagnoses, 30 had been nonetheless statistically related to autism within the youngster. To decide if these occurred to happen alongside quite than trigger autism, the researchers then included the siblings of autistic youngsters within the evaluation. If a mom was identified with the identical situation throughout pregnancies of youngsters with and with out autism, then it will recommend that components aside from her analysis had been influencing the link with autism. This step disentangled the situations that could possibly be attributable to familial components, reminiscent of genetics and environmental publicity to air pollution, from these that could be inflicting autism.
The Role of Genetics in Autism Risk
According to the researchers, genetics is a sturdy familial confounder (believable clarification) for autism. Some of the identical genes linked to depression are additionally related to autism. If a mom experiences depression throughout pregnancy and her youngster is later identified with autism, it’s extra possible because of shared genetic components quite than depression itself affecting the fetus throughout growth.
Researchers additionally analyzed fathers’ medical histories. Any affiliation between a paternal analysis and autism would most probably be attributable to familial components, for the reason that father’s direct results on a fetus postconception are possible very restricted. In truth, the researchers noticed that a lot of paternal diagnoses are simply as associated to youngster autism because the maternal diagnoses.
Fetal Complications: Early Signs, Not Causes
After accounting for the familial components, the one maternal analysis that was nonetheless strongly statistically related to autism was pregnancy problems associated to the fetus.
“Our interpretation is that these fetal diagnoses likely do not cause autism, but are instead early signs of it,” mentioned Janecka. “The predominant speculation is that autism actually begins prenatally. Even earlier than a youngster receives a analysis for autism, developmental modifications have been occurring your complete time.
Shifting the Narrative for Parents
“Many mothers of children with autism feel guilty about it,” mentioned Janecka, “thinking that they did something wrong during pregnancy, and it is heartbreaking. I think showing that these things are not going to cause autism is important and may lead to more effective ways to support autistic children and their families.”
Autism is a developmental dysfunction that usually emerges in childhood, affecting social interactions and conduct. Symptoms can range broadly and will embody lowered eye contact, problem participating in play, repetitive actions or speech, and strange responses to sensory experiences like temperature. While these traits can persist into maturity, they differ from person to person. According to federal estimates, autism impacts about 1 in 54 youngsters within the United States.
Reference: “Most associations between maternal health and autism are attributable to familial confounding” 31 January 2025, Nature Medicine.
DOI: 10.1038/s41591-024-03479-5
Funding help for the research was supplied by National Institutes of Health grants R01MH124817 and T32MH122394, Lundbeck Foundation grants R102-A9118 and R155- 2014-1724, the Seaver Foundation, and the Eunice Kennedy Shriver National Institute of Child Health and Human Development grant HD098883.
Other research co-investigators are Elias Speleman Arildskov, Jakob Grove, and Stefan Nygaard Hansen at Aarhus University in Denmark; Paul O’Reilly, Joseph Buxbaum, Abraham Reichenberg, and Sven Sandin at Icahn School of Medicine at Mount Sinai in New York City; Lisa Croen at Kaiser Permanente Northern California in Oakland; and Diana Schendel at Drexel University in Philadelphia.
