A new study suggests the effects of gestational depression could be serious.
According to a new study from the University of Michigan Medical School, a higher level of depression in mothers during pregnancy is linked to higher levels of stress hormones in addition to neurological and behavioral differences in their children at birth. Mom's pregnancy hormones may play an important role in the development of unborn children's brains.
Researchers in the UM study followed 154 pregnant women over age 20 whose depressive symptoms were assessed at 28, 32 and 37 weeks of gestation and again at birth. The women were placed in three groups: low, intermediate and high depression. The infants were then given a neurobehavioral evaluation after two weeks of being born.
“The two possibilities are that they [newborns of depressed mothers] are either more sensitive to stress and respond more vigorously to it, or that they are less able to shut down their stress response,” says the study’s lead investigator, Delia M. Vazquez, M.D., a professor of psychiatry and pediatrics at UM.
Researchers found that two-week-old babies of depressed mothers had decreased muscle tone compared to those born to mothers who weren’t depressed. These infants adjusted more quickly to stimuli (such as the sound of a bell or rattle, or the sudden appearance of light), suggesting neurological maturity.
“It’s difficult to say to what extent these differences are good or bad, or what impact they might have over a longer time frame,” said Sheila Marcus, M.D., clinical director of U-M’s Child and Adolescent Psychiatry Section and lead author of the study.
A longer-term question for researchers is how much the hormonal environment in the uterus may act as a catalyst for processes that alter the infant's gene expression, neuroendocrine development and brain circuitry. These processes may increase risk for later behavioral and psychological disorders.
For the study, researchers took samples of umbilical-cord blood immediately following birth, in which they found elevated levels of adrenocorticotropic hormone (ACTH) in babies born to depressed mothers. ACTH acts as a catalyst for the adrenal gland to produce more of the stress hormone cortisol.
Gestational depression may affect as many as 1 in 5 pregnant women. Previous studies have indicated babies born to women with severe depression may be more likely to be born prematurely or underweight and have diminished hand-to-mouth coordination.
Although a recurring problem for many sufferers, most depressive episodes can usually be effectively treated with a combination of medication and psychotherapy. Major depression is diagnosed when a person reports five or more depressive symptoms persisting for at least two weeks.
Postpartum depression is moderate to severe depression that occurs in women after delivery or up to one year after birth. Generally postpartum depression occurs within the first four weeks after delivery and affects between 8 percent and 20 percent of new mothers. Postpartum blues, on the other hand, is a less serious condition that includes feelings of anxiety, irritation, tearfulness, and restlessness. These symptoms usually go away on their own without the need for treatment.