英文科普：孕妇抑郁对胎儿的影响

The cocktail¹ of hormones³ cascading（串联，传递信息） through depressed⁴ mothers' bodies may play an important role in the development of their unborn children's brains. A higher level of depression in mothers during pregnancy⁵ was associated with higher levels of stress hormones in their children at birth, as well as with other neurological and behavioral differences, a University of Michigan-led study found.

"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," says the study's lead investigator⁶, Delia M. Vazquez, M.D., a professor of psychiatry⁷（精神病学） and pediatrics（小儿科） at the University of Michigan Medical School.

The analysis, which appears online ahead of print publication in Infant Behavior and Development, examined links between maternal⁸ depression and the development of an infants' neuroendocrine（神经内分泌的） system, which controls the body's stress response, as well as moods and emotions.

At two weeks old, researchers found that the children of depressed mothers had decreased muscle tone compared to those born to mothers who weren't depressed, yet they adjusted more quickly to stimuli⁹ like a bell, rattle¹⁰ or light – a sign of neurological maturity¹¹.

"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," says the study's lead author, Sheila Marcus, M.D., Clinical Director of U-M's Child and Adolescent Psychiatry Section.

"We're just beginning to look at these differences as part of a whole collection of data points that could be risk markers. These in turn would identify women who need attention during pregnancy or mother/infant pairs who might benefit from postpartum（产后的） programs known to support healthy infant development through mom/baby relationships."

The longer-term question for researchers is the degree to which the hormonal¹² environment in the uterus（子宫） may act as a catalyst¹³ for processes that alter infant gene¹⁴ expression, neuroendocrine development and brain circuitry – potentially setting the stage for increased risk for later behavioral and psychological disorders¹⁵.

While cautioning against alarm, the researchers recommended that mothers experiencing symptoms of depression during pregnancy talk to a therapist. They also noted¹⁶ that interventions¹⁷ aimed and mother-child bonding after birth can act as countermeasures（对策） , stimulating¹⁸ children's neurological development and lowering the possible effects of stress hormone² production early in life.

Post-partum depression is one of the most common complications of pregnancy and up to one in five women may experience symptoms of depression during pregnancy.

Along with tracking the mothers' depressive symptoms throughout gestation¹⁹（酝酿，怀孕） , U-M researchers took samples of umbilical（脐带的） cord blood right after birth. They found elevated levels of adrenocorticotropic hormone (ACTH) in babies born to mothers with depression. ACTH tells the adrenal gland²⁰ to produce the stress hormone cortisol. Cortisol levels, however, were similar in children of mothers with varying levels of depression, likely an indication of the high level of stress associated with the birth itself, the researchers note.

The impact of mothers' depression on fetuses²¹ and newborns has generated a considerable amount of research in recent years. Previous studies have shown that babies born to women with severe depression may be more likely to be born prematurely²² or underweight, have diminished（减少，削弱） hand-to-mouth coordination²³ and be less cuddly²⁴.

Methodology: The study was done on a population of 154 pregnant women, who were over the age of 20, had no plans to move in the 2-year study period, no adoption²⁵ plans, no chronic²⁶ medical conditions or medications that would impact the study, no substance abuse issues, no editing disorders and no bipolar illness. The mothers' depressive symptoms were assessed at 28, 32 and 37 weeks of gestation and again at birth. From their scores, the women were placed into three groups: low, intermediate and high depression. Blood samples were taken from the infants' umbilical cords（脐带） at birth to measure ACTH and cortisol levels. At two weeks, the infants were given a neurobehavioral evaluation²⁷ that assessed items like response to stimuli, motor skills and response to stress. Statistical²⁸ analyses were then done to look for patterns within and among the groups.