What Prenatal Plastic Exposure Did to Cord Blood in 847 Australian Babies
Primary research located and verified via PubMed.
Plastic is one of the things people are told to be careful with in pregnancy, usually without much explanation attached. The usual instructions are short: don't microwave in it, don't leave the water bottle in a hot car, and don't put hot food straight into a takeout container. The advice is sensible, and until recently most of the science behind it was about association: people with higher exposure tended to have children with more of a given symptom. A study published in September 2026 goes further than that, and the specifics turn out to be more useful than the general warning.
What the Barwon Infant Study measured
Researchers in Australia followed 847 children in the Barwon Infant Study [1]. They estimated prenatal exposure to di-(2-ethylhexyl) phthalate, usually written DEHP, a plasticizer that makes vinyl flexible and turns up in food packaging, flooring, and medical tubing. Then they examined DNA methylation in cord blood collected at birth. Methylation is a chemical tag that attaches to DNA and changes how strongly a gene gets expressed, without altering the gene itself.
Instead of testing one gene at a time, the team built two broader measures: a methylation profile score for DEHP exposure, and a network of 531 genes whose methylation moved together. Both measures accounted for part of the association between prenatal DEHP and autism and ADHD symptoms at ages 2 and 4, with the proportion mediated ranging from 0.21 to 0.80 depending on which outcome and which measure was used. The proportion mediated is the share of that link the methylation measures accounted for. That 531-gene network was enriched for neural cell-type markers, for autism and ADHD risk genes including FOXP1, SHANK2, and PLXNB1, and for targets of estrogen and glucocorticoid receptors. Enriched means those kinds of genes showed up in the network more often than chance would predict. The researchers then checked their main results against two independent datasets: blood from 66 people and postmortem brain tissue from 40.
It is important to note that this is a birth cohort, which means nobody assigned anyone to an exposure. "Causal mediation analysis" is the name of a statistical method, and it is not the same thing as a randomized trial. What these researchers demonstrated is a biologically plausible route from an exposure to an outcome, supported in three separate datasets. That is a step up from association alone, and it is several steps short of proof.
What other birth cohorts have found
In the Odense Child Cohort in Denmark, 585 mother-child pairs had phthalate metabolites measured in third-trimester urine, and the children completed IQ testing at age 7 [2]. Those in the highest third for prenatal DEHP metabolites scored 3.0 points lower than those in the lowest third (95% confidence interval -5.5 to -0.6). Three IQ points is small for any individual child, and it is the size of effect that shifts the average for a whole population when almost everyone is exposed.
The PROTECT cohort in Puerto Rico took a different approach with 199 mother-child pairs, examining phthalates as a mixture rather than one chemical at a time in toddlers aged 1 to 3 [3]. One metabolite, MCOP, contributed most, and the combined mixture tended toward worse scores across adaptive, cognitive, communication, motor, and personal-social development.
A small analysis of 81 mother-infant pairs in the Atlanta African American Maternal-Child Cohort did not match those two cohorts: it found no association between prenatal phthalate metabolites and newborn attention and arousal on their own [4]. What those authors did observe was that an association appeared among mothers with high depressive symptoms and was absent among mothers with low symptoms, though the confidence intervals were wide and the sample was small.
Exposure is a household question rather than a personal failing
The receptor detail in the Australian study is the part most relevant to my clinical work. That 531-gene network was enriched for estrogen receptor and glucocorticoid receptor targets, which are the hormone systems I spend most of my week on. A glucocorticoid receptor is one of the ways a body translates stress into gene expression. So when a separate cohort finds that maternal depressive symptoms change whether a phthalate association appears at all, that is consistent with looking at the whole person instead of one chemical at a time: the same exposure appears to do different things in different physiological contexts.
That view changes what I actually do with a patient. Trying to track down and remove a single chemical is rarely the most useful step, for the exposure is cumulative, largely structural, and mostly outside any one person's control. Things like sleep, nourishment, and stress load are the terrain an exposure acts on, and those we can influence.
These studies measured population-level patterns, never individual verdicts, and none of them can explain why any particular child is autistic or has ADHD. DEHP exposure in a modern country is close to universal. A pregnancy that has already happened is not a thing to feel guilty about.
Seven days, a different kitchen, and a measurable drop in phthalates
A 2026 randomized trial tested whether this exposure can be lowered. The PERTH trial in Western Australia randomized 60 participants for seven days to combinations of plastic-free kitchenware, low-plastic personal-care products, and food sourced to minimize plastic contact from farm to plate [5]. Urinary mono-n-butyl phthalate fell 37.5% (95% CI -55.6 to -12.0), monobenzyl phthalate fell 53.5%, and bisphenol A fell 59.7%. In the trial's observational arm of 211 people, highly processed, plastic-packaged, and canned foods were the strongest modifiable contributors.
The PERTH participants were adults, not pregnant women, and the trial measured chemical levels in urine, never child development. So the trial showed that this exposure can be lowered within a week, and it did not test whether lowering it changes a child's neurodevelopment.
Food contact is where that trial found the biggest change, so it is a sensible first place to put your effort: more fresh and minimally processed food, glass or stainless steel for hot food and for storage, and fewer canned items where a fresh or jarred version is easy to find. Swapping personal-care products produced a smaller independent effect, which makes it a reasonable second step rather than the opening one. If you are pregnant and want to think through what is practical in your own kitchen, that is a good conversation to bring to your provider.
References
Tanner S, Eisner A, Novakovic B, et al. Prenatal exposure to the plasticizer DEHP increases the likelihood of early-life autism and ADHD symptoms through epigenetic programming. Med (N Y). 2026;7(9):101291. PMID 42727573. https://doi.org/10.1016/j.medj.2026.101291 (original AANP digest link: https://www.cell.com/med/fulltext/S2666-6340%2826%2900294-1)
Vilmand M, Beck IH, Bilenberg N, et al. Prenatal and current phthalate exposure and cognitive development in 7-year-old children from the Odense Child Cohort. Neurotoxicol Teratol. 2023;96:107161. PMID 36690047. https://doi.org/10.1016/j.ntt.2023.107161
Park S, Cathey AL, Hao W, et al. Prenatal exposure to phthalate mixtures and child neurodevelopment in toddlers aged 1-3 years from the PROTECT birth cohort. Int J Hyg Environ Health. 2025;268:114599. PMID 40472722. https://doi.org/10.1016/j.ijheh.2025.114599
Springer K, Eatman JA, Brennan PA, et al. Maternal symptoms of depression and anxiety as modifiers of the relationship between prenatal phthalate exposure and infant neurodevelopment in the Atlanta African American maternal-child cohort. Brain Behav Immun Health. 2024;40:100846. PMID 39224563. https://doi.org/10.1016/j.bbih.2024.100846
Harray AJ, Lucas AD, Herrmann SE, et al. Low-plastic diet and urinary levels of plastic-associated phthalates and bisphenols: the randomized controlled PERTH Trial. Nat Med. 2026;32(5):1871-1883. PMID 42014506. https://doi.org/10.1038/s41591-026-04324-7
A note before you go
This article is educational and is not medical advice. It does not diagnose any condition and it does not replace individualized care from your own clinician. Autism and ADHD are complex, and nothing here explains any individual child's neurodevelopment. If you are pregnant, planning a pregnancy, or have questions about environmental exposures and your own health, please talk them through with your healthcare provider before changing anything. Written by Dr. Joyce Knieff, ND, LAc, of Yggdrasil Naturopathic.
If this resonates with what you're experiencing and you'd like to explore a naturopathic approach, book a consultation with our clinic.
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