By Claire Rifkin, MS, RDN, LDN
Pregnancy nutrition research offers plenty of encouraging findings, from babies responding to flavors before birth to better ways of personalizing prenatal supplements. As a registered dietitian who is also pregnant, I want to explain what these studies found and give you practical ways to use the information, without adding more pressure to eat perfectly.
So much pregnancy advice focuses on what could go wrong. Meanwhile, researchers are asking useful questions about how everyday foods may support development and how prenatal care can better meet individual needs.
Here are six findings worth understanding, including what they can tell us, what remains uncertain and how to apply them to the pregnancy you’re actually having.
1. Babies May Respond to Food Flavors Before They Are Born
The study about babies “smiling” at carrots and “crying” at kale is real, although those descriptions need some context.
In a 2022 study, researchers used 4D ultrasound at 32 and 36 weeks of pregnancy to observe fetal facial movements after participants took a capsule containing carrot or kale powder. The carrot group showed more movements classified as “laughter-face,” while the kale group showed more “cry-face” movements. A control group received neither flavor.
Those labels describe facial movements. They cannot tell us that a baby felt happy, disliked kale or was emotionally upset. The findings suggest that fetuses can respond differently to flavor exposure before birth, but they don’t establish future food preferences. journals.sagepub.com
What I find lovely about this research is the possibility that a baby’s experience with food begins well before their first bite. It gives us a glimpse of sensory development happening during pregnancy.
How to Apply This to Your Pregnancy
Include different flavors when they sound appealing. You might add cinnamon to oatmeal, use herbs in a pasta sauce or try a vegetable prepared a different way.
There is no special food rotation you need to follow. This study didn’t test whether eating more vegetables during pregnancy prevents picky eating, so you don’t need to force down kale to shape your baby’s future preferences.
If nausea has narrowed your options, work with what you can tolerate and revisit other foods as your appetite allows.
One manageable step: Choose a food you already enjoy and experiment with its preparation or seasoning. Roasted carrots, for example, might sound better than raw ones.
2. Mediterranean-Style Eating Shows Promise for Fetal Brain Development
The IMPACT BCN trial compared a Mediterranean-style eating program, a stress-reduction program and usual prenatal care in pregnancies at increased risk of having a baby who was small for gestational age.
The larger trial enrolled 1,221 participants. In this analysis, 881 underwent detailed fetal brain ultrasound at about 33 weeks. The Mediterranean diet group showed small differences in two brain measurements, including a longer corpus callosum, the structure connecting the brain’s two hemispheres.
Among 276 infants assessed at around 1 year, the diet group also had fewer scores below the screening cutoff for problem-solving. These findings are encouraging, though the ultrasound measurements themselves don’t prove better cognitive processing or predict intelligence. The smaller follow-up group also limits how confidently we can interpret the developmental results. karger.com
Participants received structured nutrition support as part of the intervention. That deserves attention, too. Making prenatal nutrition care accessible gives people help putting recommendations into practice.
How to Apply This to Your Pregnancy
Start with a meal you already eat and add a food emphasized in Mediterranean-style eating. That might mean chickpeas in pasta, walnuts in oatmeal or olive oil on cooked vegetables.
You don’t need specialty ingredients or an entirely new menu. Canned beans, frozen produce and microwaveable whole grains can make these meals easier to assemble.
You can also adapt this approach to your cultural foods and preferences. There’s no requirement to eat a particular cuisine.
One manageable step: Choose a meal you eat regularly and make one addition you’d enjoy. If figuring out what to eat feels overwhelming, a prenatal dietitian can help you build meals around your appetite, budget and needs.
3. Eating Nuts During Pregnancy Is Linked to Children’s Attention and Memory
A 2025 study from Spain’s INMA birth cohort followed 1,737 mother-child pairs, with neuropsychological assessments spanning ages 4 to 15. Higher maternal nut consumption during pregnancy was associated with better performance on measures of attention and working memory.
Working memory helps you hold and use information for a short period, such as remembering instructions while completing a task. Researchers measured specific cognitive skills; they didn’t show that eating nuts improves high school grades.
This was an observational study. Researchers recorded what participants ate instead of randomly assigning them to eat different amounts of nuts. Other differences between families could help explain the results, even after statistical adjustments. The findings support a possible relationship without proving that nuts caused the differences. pubmed.ncbi.nlm.nih.gov
How to Apply This to Your Pregnancy
If you enjoy nuts and don’t have an allergy, keep them available as an easy snack or meal addition. Sprinkle chopped nuts over yogurt, stir nut butter into oatmeal or pair a handful of nuts with fruit.
The study doesn’t establish a daily serving that will improve your child’s attention or memory. There’s no reason to track your intake against that outcome.
If nuts don’t work for you, skip them. This finding doesn’t make them a requirement for a healthy pregnancy.
One manageable step: Keep a nut or nut butter you like near something you regularly eat, so adding it takes very little effort.
4. Iron Supplements During Pregnancy Can Be More Individualized
Iron research offers an encouraging possibility: more precise treatment based on a person’s starting iron status.
In a follow-up from the ECLIPSES trial, researchers examined childhood behavior at age 4 after participants received different iron doses during pregnancy. Participants were randomized to doses within groups defined by early-pregnancy hemoglobin levels. Researchers also examined outcomes according to starting ferritin, a marker of iron stores.
In subgroup analyses, 80 milligrams daily was associated with better scores on some child behavior measures when maternal iron stores were low, but worse scores on several measures when stores were already relatively high. These outcomes were measured in the children. The study didn’t establish a universal ferritin-based dosing rule. onlinelibrary.wiley.com
Pregnancy increases iron needs, and iron deficiency anemia warrants treatment. The general pregnancy intake recommendation of 27 milligrams a day is different from a dose prescribed to treat a deficiency. ods.od.nih.gov
How to Apply This to Your Pregnancy
Bring a photo of your prenatal vitamin label and any separate iron supplement to your next appointment. Ask your provider to review your intake alongside your bloodwork.
Useful questions include:
- Does my blood count suggest anemia, and would checking ferritin help clarify my iron stores?
- Is the iron in my prenatal enough for my current needs?
- If I need treatment, what dose should I take and when should we repeat my labs?
- What should I do if iron causes nausea or constipation?
Avoid using the study’s dose or ferritin categories to choose your own treatment. Your provider can account for your results, pregnancy stage and response to supplementation.
One manageable step: Put your supplement labels and questions in one phone note before your appointment. You deserve to understand why you’re taking a supplement and how your care team will assess whether it’s working.
5. Vitamin D Research Shows Potential Benefits, With Mixed Results
Vitamin D is being studied for possible pregnancy benefits beyond its established role in calcium absorption and bone health. ods.od.nih.gov
A 2024 meta-analysis included 33 randomized trials involving 10,613 participants. Its pooled results reported about a 45% relative reduction in preeclampsia risk and a 30% relative reduction in preterm labor with vitamin D supplementation. link.springer.com
“Relative” needs some explanation. As a hypothetical example, a 45% relative reduction from a starting risk of 10% would bring that risk to 5.5%. It doesn’t mean 45 fewer cases for every 100 pregnancies, and that example isn’t the study’s measured absolute benefit.
The wider evidence is less settled than those percentages suggest. A separate 2024 Cochrane review applied a trial trustworthiness assessment and excluded many previously included studies from its analysis. It found the evidence very uncertain for preventing preeclampsia and preterm birth. www.cochrane.org
These findings make vitamin D worth continued study. They don’t establish that taking a supplement will cut an individual’s risk in half.
How to Apply This to Your Pregnancy
Check how much vitamin D your prenatal contains before adding another supplement. If you already take a separate product, include that amount when reviewing your intake with your provider.
You can ask: “Does my current prenatal meet my vitamin D needs, or do I have a reason to consider testing or additional supplementation?”
The U.S. recommended intake during pregnancy is 600 IU, or 15 micrograms, daily. Treatment for deficiency may differ. ods.od.nih.gov
Additional vitamin D should fit your care plan and should not replace prescribed prevention or prenatal monitoring.
One manageable step: Review all your supplements together so your provider can spot overlapping ingredients and explain what each product is doing for you.
6. Mediterranean-Style Eating Is Linked to Better Pregnancy Outcomes
The interest in Mediterranean-style eating extends beyond brain development.
A systematic review and meta-analysis of 23 studies examined this eating pattern in relation to pregnancy and birth outcomes. In the observational cohort studies, higher adherence was associated with 33% lower odds of preterm delivery and 23% lower odds of preeclampsia.
These are lower odds, which are related to risk but aren’t identical. The observational comparisons also cannot tell us how much changing one person’s diet would change their risk. Access to care, other health behaviors and differences between studies complicate the picture. pmc.ncbi.nlm.nih.gov
Still, the findings support continued interest in an eating pattern built around familiar foods. Mediterranean-style meals commonly include vegetables, fruit, beans, whole grains, nuts and olive oil, with fish and other protein sources. pubmed.ncbi.nlm.nih.gov
How to Apply This to Your Pregnancy
Build a few convenient meals you can return to. For example:
- Oatmeal with fruit and nut butter.
- A bean burrito with avocado and vegetables.
- Pasta with chickpeas, olive oil and cooked spinach.
- Fully cooked salmon with rice and frozen vegetables.
These meals incorporate foods emphasized in Mediterranean-style eating. The individual meals haven’t been shown to reproduce the studies’ results, and your diet can’t guarantee a complication-free pregnancy.
Make the approach flexible enough to use on a tired Tuesday. Convenience foods and familiar recipes can help you keep feeding yourself without making every meal a project.
One manageable step: Choose two meals from your usual rotation and keep their ingredients available.
Making Pregnancy Nutrition Research Useful to You
A finding can be interesting without becoming something you need to act on today. My approach is to look for a useful next step that fits the person reading it.
For food, that might be adding something to a meal you already enjoy. For supplements, it might be reviewing your prenatal label and bloodwork with your care team. You don’t need to turn all six studies into six new habits.
Research on nutrition and child development can quickly become a source of pressure. These studies describe patterns across groups. They cannot grade your pregnancy or tell you what your child’s future will look like.
I find it hopeful that researchers are asking more specific questions about prenatal nutrition, including how to make care more personal. You can be interested in the answers while making room for your appetite, your preferences and the amount of energy you have today.
References
- Ustun and colleagues. “Flavor Sensing in Utero and Emerging Discriminative Behaviors in the Human Fetus.” Psychological Science, 2022. Read the study.
- Nakaki and colleagues. “Effects of Mediterranean Diet or Mindfulness-Based Stress Reduction during Pregnancy on Fetal Brain Development Detected by Neurosonography: A Secondary Analysis of a Randomized Clinical Trial (IMPACT BCN).” Fetal Diagnosis and Therapy, published online in 2024; 2025 issue. Read the study.
- Pinar-Martí and colleagues. “Maternal prenatal nut and seafood consumption and child neuropsychological function from 4 to 15 years of age: a population-based cohort study.” The American Journal of Clinical Nutrition, 2025. Read the study.
- Iglesias-Vázquez and colleagues. “Prenatal iron supplementation adjusted to maternal iron stores reduces behavioural problems in 4-year-old children.” Maternal & Child Nutrition, published online in 2023; 2024 issue. Read the study.
- Moghib and colleagues. “Efficacy of vitamin D supplementation on the incidence of preeclampsia: a systematic review and meta-analysis.” BMC Pregnancy and Childbirth, 2024. Read the review.
- Palacios and colleagues. “Vitamin D supplementation for women during pregnancy.” Cochrane Database of Systematic Reviews, 2024. Read the review.
- National Institutes of Health, Office of Dietary Supplements. Dietary Supplements and Life Stages: Pregnancy and Iron: Health Professional Fact Sheet.
- “Association between the Maternal Mediterranean Diet and Perinatal Outcomes: A Systematic Review and Meta-Analysis.” Advances in Nutrition, published online in 2023; 2024 issue. Read the review.
- “Mediterranean-style diet in pregnant women with metabolic risk factors (ESTEEM): A pragmatic multicentre randomised trial.” PLOS Medicine, 2019. Read the study.
