High-quality diet in pregnancy associated with lower risk of fetal growth restriction, finds study

Researchers assessed the quality of a pregnant person's diet using the U.S. Department of Agriculture's Healthy Eating Index (HEI), which assigns a numeric value ranging from 0-100. A higher HEI score indicates a healthier diet, defined as one that aligns with the U.S. Government's Dietary Guidelines for Americans. The HEI has been used to study the effect of diet on conditions, such as diabetes, heart disease, and cancer, but it has not been widely used in the field of obstetrics to study pregnancy outcomes.

The study analyzed the diets of 762 people who had completed the NIH Diet History Questionnaire-II (DHQ-II) in the third trimester or within three months of delivery. The primary goal of the research was to look at the impact of diet during pregnancy on FGR.

Researchers also looked at the impact of diet on gestational hypertension, gestational diabetes, and large for gestational age (LGA). LGA is defined as infants who weigh more than 9 out of 10 babies, which can put the baby at greater risk of injury during birth and increased risk of health problems after birth.

Findings revealed that 128 of the 762 people (17 percent) had an HEI score of 70 or higher, and 634 (83 percent) had an HEI score lower than 70.

After adjusting for obesity and chronic hypertension, people with an HEI score of 70 or higher were 67 percent less likely to have FGR and 54 percent less likely to have high blood pressure in pregnancy. There was no difference in gestational diabetes or LGA.

"We know that nutrition and the food we eat has such a significant impact on health outcomes," said one of the study's authors, Xiao Yu Wang, MD, an obstetrics and gynecology resident physician at the Washington University School of Medicine in St. Louis. "What this research shows us is that HEI is another tool we can use, especially in collaboration with dieticians and nutritionists, to counsel our patients to help improve pregnancy outcomes. HEI also puts the power into the hands of the patient because the tool reveals risk factors that a patient can modify to help create a healthier pregnancy and a better pregnancy outcome."