Stressful Pregnancies May Hinder a Toddler’s Development

Babies born to women who are stressed out during pregnancy may be more likely to experience social, emotional and learning problems as they grow up, new research suggests.

“Mom’s elevated psychological distress affects not just her, but her unborn baby’s brain development,” said study author Catherine Limperopoulos, chief and director of the Developing Brain Institute at Children’s National Hospital in Washington, D.C.

The researchers followed nearly 100 pregnant women and their babies for 18 months. The women also answered questionnaires about their stress levels between 24 and 40 weeks of pregnancy, and their children underwent neurodevelopmental testing at 18 months of age.

Infants born to women who reported high stress levels showed brain changes in key areas of the developing brain, including the folds in the outer part of the brain (sulcal depth) and the left hippocampus, which is tasked with learning and memory, the study showed. These kids were more likely to have trouble regulating their emotions and showed thinking impairments.

“Changes to brain development at critical times in pregnancy can have lingering neurodevelopmental effects as these babies grow older,” Limperopoulos said.

Many things can influence the overall health and well-being of a developing fetus, which is why expectant moms are advised to take multivitamins, eat a healthy diet, keep their vaccinations current and aim for appropriate weight gain, Limperopoulos said.

“Pregnancy is a delicate balancing act, and many things can disrupt that critical balance, including maternal stress,” she said.

Exactly how a woman’s stress levels affect the developing brain of a fetus is not fully understood yet. The researchers only found an association and not a cause-and-effect link.

“Stress increases the activity of the maternal endocrine and immune systems, which can launch a maternal stress response, which, in turn, may affect placental function, blood flow or inflammatory activity while pregnant,” Limperopoulos said. (The placenta supplies oxygen and nutrients to the developing fetus.)

Now, Limperopoulos and colleagues plan to monitor the development of these infants long-term.

“Not only do we want to know if the developing brain is malleable enough to self-repair and if early mother-baby interventions give babies a helping hand, but we also want to explore which maternal interventions are most effective to help pregnant women to avoid these issues happening in the first place,” she said.

The good news is there are many things women can do on their own that are free or low-cost to reduce stress, such as getting good sleep, eating a nutritious diet, talking with a friend, and taking a moment to calm their anxiety by practicing mindfulness, yoga and breathing exercises, Limperopoulos said.

The study was published April 29 in the journal JAMA Network Open.

Two experts who were not part of the study agree that a woman’s stress during pregnancy can have lasting effects on her kids.

“This is such an important study, with a lot of implications for how we support pregnant women and young families,” said Dr. Marilyn Augustyn. She is director of the division of developmental and behavioral pediatrics at Boston University School of Medicine and Boston Medical Center.

“What happens during pregnancy affects how a child develops,” Augustyn said. “These findings should really fire up everyone to continue to increase support for younger families.”

Importantly, the new study includes direct measures of fetal brain structure, said Curt Sandman, professor emeritus in the Department of Psychiatry and Human Behavior at the University of California, Irvine.

“Maternal stress was toxic for offspring,” he said. “We now have preliminary information that these changes are independent of after-birth exposures.”

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More information

The March of Dimes offers advice on how to reduce stress during pregnancy.

SOURCES: Catherine Limperopoulos, PhD, chief, director, Developing Brain Institute, Children’s National Hospital. Washington, D.C.; Marilyn Augustyn, MD, director, division of developmental and behavioral pediatrics, Boston University School of Medicine and Boston Medical Center; Curt Sandman, PhD, professor emeritus, Department of Psychiatry and Human Behavior, University of California, Irvine; JAMA Network Open, April 29, 2022