According to research reviewed by Gram, mothers who ate excessive smoked, grilled, fried, and pickled foods during early pregnancy had significantly higher rates of babies born with heart defects in a study of 1,240 children. Certain genetic variations in babies increased heart defect risk by 1.6 to 2.7 times, but eating fish, shrimp, and beans appeared to reduce this genetic risk. Folic acid supplementation during pregnancy also offered protection against heart defects.
A Gram Research analysis of 620 children with heart defects and 620 healthy children found that mothers who ate a lot of smoked, grilled, fried, and pickled foods during early pregnancy had babies with higher rates of congenital heart disease. The study also discovered that certain genetic variations in children, combined with specific foods their mothers ate, influenced heart defect risk. Interestingly, eating fish, shrimp, and beans appeared to protect against some of these genetic risks. Folic acid supplementation during pregnancy also played a protective role. These findings suggest that maternal diet and genetics work together to influence heart health in developing babies.
Key Statistics
A 2026 case-control study of 1,240 children found that mothers who consumed excessive smoked, grilled, fried, and pickled foods during early pregnancy had significantly increased risk of giving birth to babies with congenital heart disease.
Three specific genetic variations (rs3733890, rs1316753, and rs1915706) in the BHMT gene increased congenital heart disease risk by 1.6 to 2.7 times in a 2026 study of 620 children with heart defects compared to 620 healthy children.
In a 2026 study of 1,240 children, maternal consumption of fish, shrimp, and beans showed protective effects against heart defects, particularly in babies carrying genetic variations that increased heart defect risk.
A 2026 hospital-based study of 620 children with heart defects found that folic acid supplementation during pregnancy reduced the risk of congenital heart disease in offspring.
The Quick Take
- What they studied: Whether what mothers eat during early pregnancy, folic acid supplements, and specific genes in babies affect the risk of congenital heart disease (a heart problem present at birth).
- Who participated: 620 children born with simple heart defects and their mothers, compared to 620 healthy children and their mothers. All families were treated at the same hospital in China between 2018 and 2019.
- Key finding: Mothers who frequently ate smoked, grilled, fried, and pickled foods during early pregnancy had significantly higher rates of babies born with heart defects. Certain genetic variations in babies increased heart defect risk, but eating fish, shrimp, and beans reduced this genetic risk.
- What it means for you: If you are pregnant or planning pregnancy, eating fresh, unprocessed foods and taking folic acid supplements may help protect your baby’s heart development. However, this study shows associations, not definitive proof of cause and effect. Talk to your doctor about prenatal nutrition and supplementation.
The Research Details
Researchers compared two groups of children and their mothers. One group included 620 children with congenital heart disease (heart problems present from birth) and their mothers. The other group included 620 healthy children and their mothers, all treated at the same hospital. Mothers answered detailed questions about what they ate during early pregnancy, whether they took folic acid supplements, and other health information. Doctors also took blood samples from the children to test for specific genetic variations related to how the body processes certain nutrients. Researchers then used statistical analysis to find connections between maternal diet, folic acid use, genetic variations, and heart defect risk.
This research approach is important because it looks at real-world situations rather than controlled laboratory settings. By comparing children with and without heart defects, researchers can identify patterns in what mothers ate and what genes children had. This helps doctors understand whether diet and genetics work together to influence heart health before birth. The genetic testing adds another layer of understanding, showing that the same food might affect different babies differently based on their genes.
This study has several strengths: it included a large number of participants (1,240 total), used a structured questionnaire to collect consistent information, and tested for specific genetic markers. However, mothers were asked to remember what they ate during pregnancy, which can be inaccurate. The study was conducted in one hospital in China, so results may not apply equally to all populations. The researchers corrected for multiple statistical tests to reduce false findings, which strengthens confidence in the results.
What the Results Show
Mothers who ate excessive amounts of smoked foods, barbecued foods, fried foods, and pickled vegetables during early pregnancy had significantly higher risk of giving birth to babies with heart defects. The risk increased with the amount of these foods consumed. Three specific genetic variations in children (rs3733890, rs1316753, and rs1915706) were strongly associated with increased heart defect risk. Children carrying certain versions of these genes had 1.6 to 2.7 times higher risk of heart defects compared to children without these genetic variations. These genetic effects were similar across different types of heart defects, including atrial septal defect (hole between upper heart chambers) and ventricular septal defect (hole between lower heart chambers).
Folic acid supplementation during pregnancy appeared protective against heart defects, particularly in mothers who might have had inadequate dietary folate intake. Interestingly, when mothers ate fish, shrimp, and beans, these foods seemed to reduce the increased heart defect risk associated with certain genetic variations. This suggests that diet and genetics interact with each other. The protective effect of these foods was strongest in children carrying the high-risk genetic variations, suggesting that certain nutrients in fish, shrimp, and beans may help counteract genetic vulnerability.
This research builds on existing knowledge that maternal diet during pregnancy influences fetal development. Previous studies have shown that processed foods and inadequate folic acid increase birth defect risk, while healthy diets protect fetal health. This study adds new information by identifying specific genetic variations that make some babies more vulnerable to dietary effects. The finding that certain foods can offset genetic risk is relatively novel and suggests that even babies with genetic predisposition may be protected through maternal nutrition.
Mothers were asked to recall what they ate during pregnancy, which can be inaccurate or biased. The study was conducted at one hospital in China, so results may not apply to other populations with different genetic backgrounds or dietary patterns. The study shows associations between diet, genes, and heart defects, but cannot prove that diet directly causes the defects. Other unmeasured factors (such as maternal infections, medications, or environmental exposures) could influence results. The study did not measure actual nutrient levels in mothers’ blood, only dietary intake based on memory.
The Bottom Line
Pregnant women and those planning pregnancy should eat a diet rich in fresh, unprocessed foods including fish, shrimp, beans, and vegetables. Take folic acid supplements as recommended by your healthcare provider (typically 400 micrograms daily before and during pregnancy). Limit or avoid smoked, grilled, fried, and heavily processed foods, especially during early pregnancy when the baby’s heart is developing. These recommendations are supported by this research and align with general prenatal nutrition guidelines, though individual needs vary.
Women who are pregnant or planning to become pregnant should pay attention to these findings. Women with a family history of heart defects may benefit especially from optimizing nutrition and folic acid intake. Healthcare providers caring for pregnant women should consider discussing these dietary patterns with patients. The findings are most directly applicable to populations with similar genetic backgrounds to the study population, though the general principle that maternal diet affects fetal development applies broadly.
Heart development occurs primarily during the first 8 weeks of pregnancy, so dietary choices during this early period are most critical. However, good nutrition throughout pregnancy supports overall fetal development. Benefits of folic acid supplementation are most pronounced when started before pregnancy or in the first trimester. You would not see immediate changes, but rather reduced risk of birth defects at delivery.
Frequently Asked Questions
What foods should pregnant women avoid to protect their baby’s heart?
Limit smoked meats, grilled and fried foods, and pickled vegetables during early pregnancy when the baby’s heart develops. A 2026 study found mothers eating excessive amounts of these processed foods had higher rates of babies with heart defects.
Does folic acid really prevent heart defects in babies?
Folic acid supplementation during pregnancy appears protective against heart defects according to a 2026 study of 1,240 children. Take 400 micrograms daily as recommended by your healthcare provider, especially before conception and during the first trimester.
Can eating fish and beans during pregnancy help prevent birth defects?
A 2026 study found that maternal consumption of fish, shrimp, and beans reduced heart defect risk, particularly in babies with genetic variations that increased vulnerability. These foods appear to offer protective effects through their nutrient content.
Are some babies genetically more at risk for heart defects from poor maternal diet?
Yes, a 2026 study identified three genetic variations that increased heart defect risk 1.6 to 2.7 times. However, eating protective foods like fish, shrimp, and beans reduced this genetic risk, showing that diet and genes interact.
When during pregnancy is diet most important for heart development?
Early pregnancy is most critical since the baby’s heart develops primarily during the first 8 weeks. However, maintaining good nutrition throughout pregnancy supports overall fetal development and health.
Want to Apply This Research?
- Log daily food intake during pregnancy, specifically tracking servings of processed/fried foods versus fresh fish, shrimp, beans, and vegetables. Set a goal to limit processed foods to fewer than 2 servings per week and increase protective foods to at least 5 servings per week.
- Use the app to set reminders for daily folic acid supplementation and to log meals before eating. Create a simple checklist of healthy foods to buy at the grocery store (fish, shrimp, beans, fresh vegetables) and processed foods to avoid (smoked meats, fried foods, pickled items). Track weekly compliance with these dietary goals.
- Review weekly nutrition reports showing the ratio of processed foods to protective foods consumed. Set progressive goals to reduce processed food intake by 10-20% each month while increasing fish, shrimp, and bean consumption. Share reports with healthcare provider at prenatal visits to discuss dietary patterns and any needed adjustments.
This research shows associations between maternal diet, genetics, and heart defects, but does not prove direct cause and effect. Individual risk factors vary based on genetics, overall health, and other environmental factors. Pregnant women should consult with their healthcare provider before making significant dietary changes or starting supplements. This article is for educational purposes and should not replace professional medical advice. If you are pregnant or planning pregnancy, discuss prenatal nutrition and supplementation with your doctor.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.