May 17, 2006 -- Pregnant women may have one less thing to worry about, new research shows.
In the May/June issue of Child Development, researchers report that in healthy pregnant women, mild to moderate amounts of psychological may slightly help -- and not harm -- babies' development.
"These findings do not support the notion that maternal anxiety, , or nonspecific stress during within normal limits poses a significant threat to early child development or behavioral regulation," write Janet DiPietro, PhD, and colleagues in the journal.
DiPietro is a professor at the Johns Hopkins Bloomberg School of Public Health.
"In contrast, we found modest, although consistent, support that these aspects of maternal psychological functioning are associated with more optimal early child development," the researchers add, emphasizing that the benefits to babies were "small."
Stressed and Pregnant
The study included 94 women who took psychological tests during their pregnancy (at 24, 28, or 32 weeks) and again six weeks and two years after giving birth. The babies born from those pregnancies took developmental and behavioral tests when they were 2 years old.
The women were at least 20 years old (average age: 32); each was pregnant with only one child. Most were white. Women who experienced pregnancy-related medical conditions or complications (such as preterm labor) were not included in the study.or
DiPietro's team calls the mothers-to-be "well-nourished, financially stable women with wanted pregnancies" who didn't endure traumas during pregnancy and didn't show clinical levels of anxiety and depression.
The women took surveys on anxiety, depression, stress unrelated to pregnancy (such as car breakdowns), pregnancy-specific stress (such as making nursery arrangements), and attitudes toward pregnancy.
The researchers predicted that maternal stress during pregnancy would be associated with slower child development, since that's what tests on animals (including rats and monkeys) have shown. But those predictions missed the mark.
Stress and Child Development
Mild to moderate levels of maternal stress duringweren't associated with slower child development or behavioral problems. In fact, such stress was linked to slightly better performance on behavioral and motor skills tests taken by the babies when they were 2 years old.
"However, the beneficial effects attributable to prenatal psychological factors, when detected, were small, ranging from only 5.5% to 6.8% of the variance," write the researchers. By "variance," they mean the gap in the kids' test results.
Kids' hyperactivity wasn't associated with maternal stress during pregnancy.
"Our findings may provide relief to those concerned about the psychological implications for pregnant women of yet another pregnancy threat, in this case, causing women to worry about worrying," write DiPietro and colleagues.
Exception to the Findings
One group of mothers -- those who viewed their pregnancies negatively -- stood out.
Those women's babies "showed slower psychomotor development and poorer emotional and attentional regulation during testing," the researchers write.
The researchers can't tell if those kids' test results were influenced by how the mothers treated those children. "That is, women who regard their pregnancy more negatively may be less likely to interact with their child in ways that foster development and socioemotional regulation," write DiPietro and colleagues.
Of course, the findings don't describe all children or mothers-to-be. The researchers aren't promoting maternal stress or drawing a direct line between maternal stress and kids' development.
It's also not clear how modest levels of maternal stress during pregnancy might enhance child development.
Possibly, babies in the womb might get additional stimulation as their mothers' bodies cope with mild to moderate amounts of stress, but too much stimulation may "overwhelm the response capabilities of the fetus," the researchers write.