Depression during pregnancy linked to highly stress-sensitive and hypotonic babies
Mothers who demonstrate depressive symptoms even if they don’t have a major depressive disorder can have offspring that have altered neurologic development compared to nondepressed women.
This connection between maternal depression and the body system (limbic-hypothalamic-pituitary axis (LHPA) of the neuroendocrine system) that controls reactions to stress, including moods and reactions, is explored in a study funded by the National Institutes of Health and published in Infant Behavior and Development.
In the analysis, 154 pregnant women were monitored for depressive symptoms (low/stable, intermediate or high/increasing depression) at various stages of pregnancy (28, 32 and 37 weeks of gestation) and at delivery. The newborns were also examined for levels of adrenocorticotropic hormone (ACTH) and cortisol using their umbilical cord blood. ACTH stimulates the adrenal gland to release the stress hormone cortisol.
Infants born to women with high depression have elevated ACTH. However, the level of the stress hormone cortisol is the same for all children, although their mothers have varying levels of depression. The researchers think that this might also be associated with the stress during childbirth itself.
At 2 weeks old, an evaluation was conducted on the infants assessing responses to stress and stimuli, tone and reflexes and motor skills to determine developmental and behavioral maturation. On examination, the children had decreased muscle tone, though they respond well to visual and auditory stimuli like light or a bell and rattle, which signals neurologic maturity.
However, the researchers found that mothers who have a high level of depression have infants showing high levels of stress hormones at birth and other developmental and behavioral differences, compared to nondepressed mothers.
Research investigator Dr. Delia M. Vazquez, a professor of psychiatry and pediatrics at the University of Michigan Medical School says, “The two possibilities are that they are either more sensitive to stress and respond more vigorously to it, or that they are less able to shut down their stress response.”
The researchers recommended talking to a therapist when depressed during pregnancy and mother-child bonding after birth to stimulate the child’s neurologic development and counteract the effects of early stress hormone production.