Stress during pregnancy can influence how Duchenne muscular dystrophy (DMD) develops in offspring, according to new research in mice published recently in iScience. The study found that while prenatal stress did not worsen muscle symptoms, it did increase anxiety and lower bone mass in mice with DMD. Surprisingly, stress in the womb also seemed to protect these mice from dangerous drops in blood pressure when faced with physical stress later in life.
Researchers studied a mouse model of DMD by breeding female carriers of the disease with healthy males. To mimic the kind of stress pregnant women might experience, some mice were gently restrained during the final week of pregnancy. Their male offspring were then monitored for six months to track physical and behavioral development.
“[B]y investigating DMD-affected and healthy offspring born to DMD carrier mothers, genotype-specific effects were identified, providing emphasis on the effect of offspring genetics on fetal programming outcomes,” explained the authors of this study. They continued, “We highlight the central, autonomic, and peripheral phenotypes that are influenced by prenatal stress in healthy male offspring and in hereditary conditions such as DMD.”
The results showed that mice with DMD born to stressed mothers had stronger cardiovascular responses to physical stress than those born to non-stressed mothers. Their blood pressure increased more appropriately and their heart rates were lower under strain, helping them survive acute stress better than expected. This is particularly important in DMD, where a weak response to stress can lead to sudden health issues.
Read more about DMD prognosis
However, the same prenatal stress led to increased anxiety-like behavior and lighter bones in DMD offspring. These mice moved less in open spaces and showed signs of heightened emotional sensitivity. Anxiety and behavioral difficulties affect many people with DMD, and this study suggests that stress during pregnancy might make these issues more severe.
Muscle size and strength, the hallmark problems in DMD, were not affected by prenatal stress. DMD mice had larger leg muscles compared to healthy mice, as is typical in this disease model, and those muscles grew predictably over time whether or not their mothers had experienced stress.
The researchers believe that prenatal stress may “program” the body’s systems in complex ways depending on the genetic makeup of the baby. For people affected by DMD, this study points to the importance of maternal well-being during pregnancy, especially when a hereditary condition is involved. While more research is needed in humans, these results highlight that stress in pregnancy could have long-lasting effects — some of which may be harmful, and others unexpectedly helpful — on children at risk for serious inherited diseases such as DMD.
Sign up here to get the latest news, perspectives, and information about DMD sent directly to your inbox. Registration is free and only takes a minute.
