A recent study reveals that stress experienced by the father before conception may leave traces on fetal development, not through changes in DNA, but through subtle molecular signals within sperm.
The study, conducted by the University of Colorado Anschutz, reveals that sperm contain small molecules affected by life experiences, including a molecule known as let-7f-5p, the levels of which rise in response to stress. Researchers believe this molecule may influence early embryonic development, subsequently impacting the child's development after birth.
In experiments with mice, the team increased the level of this molecule in fertilized eggs to mimic the effects of parental stress. They found that the resulting males were larger and had longer bones, even though they consumed normal amounts of food, suggesting that the changes were not related to nutrition.
The results indicate that sperm not only carry genetic material, but also carry biological signals that are influenced by the father’s lifestyle and psychological experience, including stress.
Dr. Tracy Bell, the study's lead researcher from the University of Colorado Anschutz, said: "These findings show that sperm carry information beyond DNA, including traces of the father's experiences that may affect the embryo's long-term development and health."
As Dr. Neil Epperson, one of the study's participants, explained, these findings add to the growing evidence that the period preceding pregnancy is not biologically neutral, but may be influenced by life experiences, including chronic stress.
He added that stress does not change the genes themselves, but it may change the way they function through molecular signals in reproductive cells, which may be reflected in the early stages of fetal development.
This study builds on previous research showing that parental stress may be linked to changes in brain development, behavior, and metabolism in offspring. The new study adds another dimension by suggesting it may also affect physical development, such as body size and bone growth.
Researchers believe that chronic stress, such as work pressures, financial burdens, or caring for a sick person, may raise the levels of these molecules in sperm, which may have indirect effects on the fetus.
The researchers emphasize that these findings highlight the importance of mental and physical health before pregnancy, noting that stress management, good sleep, and proper nutrition may contribute to providing a better biological environment for reproduction.
