Researchers at Oregon Health & Science University's Center for Mental Health Innovation have discovered that maternal diet during pregnancy, specifically during the third trimester, may be associated with a higher risk for mental health disorders in offspring. These findings add to the growing evidence that maternal health factors influence infant neurodevelopment, meaning how the brain forms and functions.
The study, published in Scientific Reports, assessed the effects of second- and third-trimester maternal diet on child behavioral outcomes. It confirmed that consumption of high-glycemic index foods, or foods causing a rapid rise in blood sugar levels, during pregnancy could impact infant temperament and behavioral trajectories.
The study is part of ongoing efforts led by Elinor Sullivan, Ph.D., professor of psychiatry and behavioral neuroscience in the OHSU School of Medicine, and Hanna Gustafsson, Ph.D., associate professor of psychiatry in the OHSU School of Medicine, to understand how environmental factors during pregnancy influence fetal brain development.
"These findings highlight opportunities to enhance nutrition during pregnancy and improve offspring outcomes by providing specific dietary targets and timepoints that can make a difference in infant behavioral health," said lead author Elizabeth Wood, Ph.D., assistant professor of psychiatry in the OHSU School of Medicine. "They also further emphasize the critical importance of policies and systems that support access, affordability and education around consuming healthy diets during pregnancy.
"By advancing interventions that focus on optimizing nutrition during pregnancy, we can better support a baby's developing brain."
In this ongoing study, researchers examined the influence of maternal health factors on infant neurodevelopment. More than 300 study participants reported their dietary intake; completed an in-laboratory body composition assessment; and provided blood samples during the second and third trimesters.
Dietary intakes were then entered into a database to calculate exact nutritional composition and create a composite average of each participant's glycemic index, also known as blood sugar levels. High-glycemic-index foods include items like packaged breakfast cereals and bars, white bread, chips and crackers, while low-glycemic-index foods include items like fruits and vegetables, beans, nuts and minimally processed grains.
When study participants' infants were approximately 6 months old, caregivers completed a questionnaire to explore infant behavioral characteristics and temperament in the home environment. They were also brought into the lab for evaluations, at which point researchers performed standard assessments to examine behaviors used to regulate emotions, which are strong indicators of risk for mental health disorders in early life.
On both measures, the findings revealed a significant link between higher dietary glycemic index and risk for mental health disorders. Interestingly, these effects were only present in the third trimester; this suggests a potentially sensitive period for dietary needs during pregnancy, and highlights the value of recommending maternal dietary modifications at specific pregnancy stages.
"As a physician, my goal is to help patients feel that they have optimized their food choices so their child can have the healthiest start in life," said Jamie Lo, M.D., MCR, associate professor of obstetrics and gynecology in the OHSU School of Medicine, who specializes in maternal-fetal medicine. "While we know nutrition is important throughout the entire pregnancy, these findings indicate the third trimester is a critical window for maternal dietary quality.
"As it is common for patients to establish prenatal care after the first trimester," Lo continued, "this presents an opportunity for health care providers to still intervene during pregnancy, and potentially improve mental health outcomes in children."
To promote healthy nutrition during pregnancy, experts at the OHSU Center for Women's Health developed the My Pregnancy Plate model, which emphasizes balance, variety and moderation. The center also offers one-on-one counseling with a registered dietitian to support patients' nutritional needs and goals.
Looking ahead, the team hopes this study and future related research will provide information on the optimal diet to consume during pregnancy, improve access to healthy foods, and optimize potential nutritional interventions during pregnancy to positively influence the health of mothers and babies.
"If you intervene during pregnancy, you're offering knowledge and tools not only to the pregnant person, but also to their child and then potentially their children after that," Sullivan said. "You're shaping the health of generations to come."
