Articles Root Causes & Stressors Toxicity Preconception, Prenatal Exposures and TILT (Toxicant-Induced Loss of Tolerance)

Preconception, Prenatal Exposures and TILT (Toxicant-Induced Loss of Tolerance)

Prenatal Exposure to Toxins Can Affect a Child’s Neurodevelopment

Did you know that a parents’ exposure to toxins pre-conception and prenatally may play a role in priming their child’s immune system to be more reactive? This immune priming can have huge implications for a child’s neurodevelopment.

We are exposed to innumerable synthetic toxins in everyday life. Things we use every day in our personal care products and in our homes can be wreaking havoc on our immune systems and this effect can be multigenerational. Some of these toxins include:

Perfumes and synthetic fragrances found in soaps, shampoos, laundry detergent, cleaners
Fragranced candles, sprays and “plug in” air fresheners
Dishwashing detergents and household cleaners, including bleach and ammonia
Preservatives, and stabilizers in cosmetics and personal care products
Toothpaste, mouthwashes, and even dental floss (which are lined with endocrine disrupting chemicals!)
Cosmetics, creams, and lotions
Paints, solvents, nail polish

Dr. Claudia Miller’s TILT (Toxicant-Induced Loss of Tolerance) Hypothesis

Dr. Claudia S. Miller, a physician-researcher at UT Health-San Antonio, hypothesizes that parents’ exposure to certain toxic substances before conception may increase the risk of their children developing neurodevelopmental disorders like autism and ADHD. Her 2024 study utilized the Quick Environmental Exposure and Sensitivity Inventory (QEESI), a questionnaire designed to identify individuals with chemical intolerance, to assess the relationship between a parent’s chemical sensitivity and their children’s health outcomes. The study found that parents with high chemical intolerance scores were 5.7 times more likely to report having a child with autism and 2.1 times more likely to report a child with ADHD compared to those with low scores.

Dr. Miller’s TILT hypothesis—Toxicant-Induced Loss of Tolerance—explains how repeated or intense chemical exposures can cause a person to become hypersensitive to even tiny amounts of everyday chemicals. This condition can disrupt the body’s immune and nervous systems, particularly by over-activating mast cells, which release inflammatory substances in response to perceived threats.

How does a parent’s chemical or toxin exposure lead to inflammation or neurodevelopmental issues in a child?

When a parent—especially the mother—experiences TILT before or during pregnancy, her body may exist in a state of chronic inflammation. This altered immune environment, along with possible disruptions in hormone balance, microbiome balance, nutrient absorption, and other factors can affect the developing fetus. These inflammatory and chemical stressors during critical windows of brain development may increase the risk of conditions like autism and ADHD in the child.

Toxicant-Induced Loss of Tolerance

Toxicant Induced Loss of Tolerance (TILT) is a two-stage process:

Initiation: A significant exposure to a chemical or a series of low-level exposures disrupts the body’s ability to tolerate substances previously deemed harmless.
Triggering: After this loss of tolerance, even minimal exposures to various substances, including foods, drugs, or environmental chemicals, can provoke a range of inflammatory symptoms across multiple organ systems.

Published with the permission of Dr. Claudia Miller.

Once the tolerance has been lost, the immune system is easily primed to precipitate a state of inflammation whenever it encounters even small amounts of a toxin. This predisposition for inflammation is passed along to offspring in utero and epigenetically.

The TILT hypothesis suggests that reducing parents’ toxic exposures before conception and during pregnancy may lower this risk by creating a healthier developmental environment for the baby.

Quick Environmental Exposure and Sensitivity Inventory (QEESI)

To identify and assess chemical intolerance, Dr. Miller developed the Quick Environmental Exposure and Sensitivity Inventory (QEESI). This self-administered questionnaire evaluates the severity of symptoms, chemical intolerances, other intolerances (like foods and drugs), and life impact. The QEESI has been validated and is widely used in both clinical and research settings to differentiate individuals with chemical intolerance from the general population. Dr. Miller has discovered that parents of children with neurodevelopmental disorders such as ASD and ADHD generally score higher on the QEESI, indicating they have experienced prior immune activation that may have had an influence on their children’s neurodevelopment.

You can take the QEESI (less than 5 minutes) via an online questionnaire: https://www.haywardscore.com/qeesi-symptom-star/landing-beta

About Beth Lambert

Beth Lambert is a former healthcare consultant and teacher. As a consultant, she worked with pharmaceutical, medical device, diagnostic and other health care companies to evaluate industry trends.

She is the author of A Compromised Generation: The Epidemic of Chronic Illness in America’s Children (Sentient Publications, 2010). She is also a co-author of Documenting Hope's Brain Under Attack: A Resource for Parents and Caregivers of Children with PANS, PANDAS, and Autoimmune Encephalitis. She is a co-author of Reversal of Autism Symptoms among Dizygotic Twins through a Personalized Lifestyle and Environmental Modification Approach: A Case Report and Review of the Literature, J. Pers. Med. 2024, 14(6), 641.

In 2009, Beth founded Documenting Hope and currently serves as Executive Director. Beth attended Oxford University, graduated from Williams College and holds a Masters Degree in American Studies from Fairfield University.

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