How a Mother’s Diet During Pregnancy May Affect a Child’s Autism Risk

A healthy, well-rounded prenatal diet, including the occasional indulgence in cravings, is key to a baby’s healthy brain development.

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Before a baby takes its first breath, its brain is already taking shape, built from the nutrients in its mother’s bloodstream.

A growing body of evidence suggests that maternal nutrition plays a measurable role in how a baby’s brain develops and, increasingly, in a child’s risk of autism and other neurodevelopmental conditions.

In one of the largest cohort studies on the subject, researchers followed more than 80,000 mother-infant pairs. Children born to mothers with the healthiest diets during pregnancy were found to be 22 percent less likely to receive an autism diagnosis.

Why Diet Matters So Much in Pregnancy

During pregnancy, a baby depends entirely on its mother for the nutrients needed to build and mature its organs. That dependence is part of why nutrition has drawn so much scientific interest.

“[Nutrition] can influence fetal development through epigenetic mechanisms; biological processes that regulate how genes are expressed without altering the underlying genetic code,” Dr. Nadia Baker, a psychiatrist, told The Epoch Times.

The cohort study published on JAMA Network Open found that mothers who followed a healthier dietary pattern were less likely to have children diagnosed with autism or to report social communication difficulties at ages 3 and 8.

Researchers point to two main pathways connecting maternal diet to brain development. One is poor nutrition, as it can contribute to inflammation during pregnancy, which in turn may affect the developing brain through oxidative damage.

The second pathway is nutrient transfer through the placenta—omega-3 fatty acids and micronutrients such as iron, choline, iodine, zinc, and vitamins B, D, and E pass from mother to baby this way.

“These nutrients need to be obtained from the maternal diet or supplements since they cannot be synthesized,” Rebecca Schmidt, a molecular epidemiologist and professor at the University of California, Davis, told The Epoch Times. A lack of them can, therefore, impact the developing brain, though no single nutrient is responsible for healthy brain development on its own.

Nor does research suggest that diet alone causes autism, David Horner, a postdoctoral fellow at the University of Copenhagen who has studied autism and maternal diet, told The Epoch Times. Rather, nutrition may be one environmental factor interacting with genetic vulnerability.

When Nutrition Matters Most

Early to mid-pregnancy appears to be a particularly important window for brain development. During the first and second trimesters, the brain and spinal cord form, new brain cells are produced, and those cells migrate to their correct locations.

“Early brain development happens before many women even know they are pregnant,” Tom O’Bryan, a functional medicine expert and researcher in chronic disease and neuroinflammation, told The Epoch Times. During the early stage, the baby’s blood-brain barrier is still developing and more permeable, meaning it may be more sensitive to what is happening in the mother’s body, he said.

The nutrients that matter most also shift over time. Folic acid is especially important around conception and in early pregnancy. Vitamin D appears particularly important in early pregnancy, while omega-3s and iron play a larger role in the second and third trimesters, according to Schmidt.

Nutrition matters even before conception, Catherine Friel, dietitian and researcher at the University of Glasgow, told The Epoch Times. Building adequate nutrient stores beforehand helps ensure the fetus has what it needs from the very start.

What Studies Have Shown About Dietary Patterns

Large studies have compared broad dietary patterns rather than individual nutrients, and the contrast is clear.

A Western-style diet during pregnancy, typically high in processed foods, added sugar, and unhealthy fats, has been linked to a higher risk of both ADHD and autism. A review of three large studies including more than 60,000 mother-child pairs found the Western-style eating pattern was associated with increased autism-related outcomes in children up to age 10.

By contrast, greater adherence to a Mediterranean diet around the time of conception has been associated with lower odds of autism-related behavioral outcomes.

“The fetal brain isn’t just growing during pregnancy; it’s already functioning, and maternal nutrition is actively shaping that function in real time,” Jessica Clancy-Strawn, a registered dietitian who has worked extensively with pregnant women, told The Epoch Times.

Cravings, Real Life, and Nutrient Gaps

So what changes can expectant mothers make?

“As a mom, a dietitian, and someone who experienced multiple pregnancy losses before finally delivering a live baby in a high-risk pregnancy, I know how important it feels to do everything you can to support your baby’s development,” Clancy-Strawn said.

During her own pregnancy, she focused on nutrients that support brain development: eggs for choline, B12, vitamin D, and protein; fatty fish such as salmon for DHA; leafy greens and legumes for folate and iron; dairy or fortified plant milks for iodine and calcium; nuts, seeds, and plant oils for healthy fats and magnesium; and whole grains, fruits, and vegetables for fiber and antioxidants.

Pregnancy does not have to mean restriction. Cravings are a very normal part of pregnancy, and they often show up in specific and strong ways, Clancy-Strawn said.

“When I was pregnant, I craved fajita nachos with queso, not shredded cheese, but the melted kind, plus refried beans and all the veggies. And when that craving hit, nothing else satisfied it,” she said.

Pregnancy brings major shifts in hormones, metabolism, and appetite, and cravings can be one way the body responds to those changes. Rather than fighting them, Clancy-Strawn suggested allowing space for cravings within a healthy diet. What matters most is the overall pattern of eating. When daily meals are built around nutrient-dense foods, there is still room for cravings without throwing things off balance, she said.

Nutrient risks can go unnoticed during pregnancy. The body’s increased demands can create deficiencies, and some commonly used medications, including acid reducers and metformin, can interfere with B vitamin absorption. High caffeine intake and alcohol can increase nutrient loss as well, Clancy-Strawn said.

Building a Brain-Healthy Plate

It would be easy to find these recommendations something for pregnant women to worry about. However, experts say there is no need to worry.

Rather than making mothers feel guilty or overwhelmed, a more constructive approach is to help them to make healthy dietary choices more affordable and accessible, Horner said.

Morten Arendt Rasmussen, a professor of computational food and health science at the University of Copenhagen, told The Epoch Times that a bit of effort, willpower, and local or family support can help a pregnancy diet be both nutritious and satisfying.

Clancy-Strawn shared the following example of a day’s eating to support fetal brain development:

• Breakfast: 2 eggs with whole‑grain toast and avocado; optional DHA-fortified milk or a cup of coffee (or decaffeinated coffee or tea) with added DHA
• Mid‑Morning Snack: Greek yogurt with chia seeds or walnuts and berries
• Lunch: Mediterranean salmon bowl with quinoa, spinach or kale, and olive oil
• Afternoon Snack: Hummus with vegetables and whole‑grain crackers
• Dinner: Grilled chicken or tofu, roasted sweet potatoes, steamed broccoli or Brussels sprouts, mixed‑greens salad with pumpkin seeds
• Evening Option: Fortified milk or plant‑milk latte

“This pattern naturally delivers nutrients linked to healthy fetal brain development and supports placental and metabolic health,” Clancy-Strawn said.

The key message is that nutrition provides an important foundation for healthy brain development, Baker said. “While no single dietary factor can prevent or cause autism, ensuring adequate intake of essential nutrients and following evidence-based prenatal care recommendations are practical steps that support both maternal health and optimal fetal development.”