By Elodie Vaz | Published on April 29,
2026 | 4 min read
Pregnancy is a key period
of “developmental programming,” during which the maternal environment can have
lasting effects on a child’s health. It is already known that physical activity
during pregnancy improves the offspring’s metabolism, notably by reducing the
risk of obesity and energy balance disorders. Conversely, prenatal stress is
suspected to disrupt this programming by altering the hormonal and metabolic
signals transmitted to the fetus.
A new study published on
April 22 in The FASEB Journal suggests that these two factors interact:
in mice, maternal stress may diminish the metabolic benefits of exercise for
the offspring, particularly in males.
Understanding the
combined effect of stress and exercise
The researchers aimed to
determine how psychosocial stress during pregnancy influences the
well-established beneficial effects of maternal exercise on the metabolic
health of offspring.
The challenge is twofold:
to observe metabolic outcomes in the offspring and to identify the underlying
biological mechanisms. The authors focused in particular on brown adipose
tissue, a “beneficial” fat that burns energy to produce heat, unlike white adipose
tissue, which stores calories.
Focus on
corticosteroids
The study, titled Distinct
effects of maternal stress and exercise on offspring metabolic health, was
conducted using a mouse model. Pregnant females were exposed to different
experimental conditions combining physical activity and prenatal stress.
The researchers then
assessed the metabolic health of the offspring, analyzing differences based on
sex. They also examined molecular pathways in brown adipose tissue, with a
focus on corticosteroids—hormones essential for regulating energy balance and many
physiological processes.
Reduced exercise
benefits in males
The results show that
exercise during pregnancy does improve the metabolic health of offspring.
However, these benefits are reduced when the mother is exposed to prenatal
stress.
This effect appears
particularly pronounced in male offspring, suggesting a sex-specific
vulnerability in metabolic programming.
Mechanistically, maternal
stress may alter corticosteroid signaling pathways in the offspring’s brown
adipose tissue. This alteration could limit the tissue’s ability to burn
energy, thereby compromising the metabolic benefits normally induced by exercise.
As the authors note,
“This work provides a framework for understanding how psychosocial factors can
modify exercise-based interventions during pregnancy and highlights the
importance of considering maternal stress context in studies of developmental
metabolic programming.”
New perspectives for
preventing metabolic diseases
These findings reinforce
the idea that a child’s metabolic health begins to take shape in utero, under
the combined influence of biological, behavioral, and psychosocial factors.
Although these results
still need to be confirmed in humans, they open new avenues for preventing
metabolic diseases. In the future, recommendations regarding physical activity
during pregnancy may need to more systematically incorporate the management of
maternal stress in order to optimize benefits for future generations.
Read next: Mpox
and pregnancy: a risk for the fetus?
About the Author – Elodie Vaz
Health journalist, CFPJ graduate (2023).
Élodie explores the marks diseases leave on bodies and, more broadly, on
human life. A registered nurse since 2010, she spent twelve years at patients’
bedsides before exchanging her stethoscope for a notebook. She now investigates
the links between environment and health, convinced that the vitality of life
cannot be reduced to that of humans
