By Megan Rauscher
Maternal depression during pregnancy "has a negative impact on children's cognitive development, even when postnatal (after delivery) depression has been taken into account," Dr. Toity Deave told Reuters Health.
"It is widely acknowledged that postnatal depression has a negative impact on child development but this is the first study that has demonstrated that the children of women who experience low mood during pregnancy are also at risk," said Deave, from the Centre for Child and Adolescent Health, University of the West of England, Bristol.
The findings come from a long-term study of 9 244 women and their children. A total of 1 565 women, or 14 percent, suffered from depression while pregnant but not after two months following delivery, Dave and colleagues report in the medical journal BJOG.
Standard developmental screening tests in the children showed that 893, or nine percent, were developmentally delayed at age 18 months. A developmental delay is any significant lag in a child's physical, cognitive, behavioural, emotional, or social development, in comparison with established normal ranges for his or her age.
Deave and colleagues found that persistent depression in the mother during pregnancy increased the odds of developmental delay in the son or daughter by 50 percent.
After factoring in the effects of depression early after delivery, the researchers say they found evidence of an "independent and statistically significant" 34 percent increase in the odds of developmental delay in children of mothers who were depressed while pregnant.
This study, they say, adds to "increasing evidence that the mother's mood during pregnancy is important" and that any persistent depression during pregnancy has the potential to raise the risk for developmental delay in childhood.
"For the women who might be worried reading this, I would recommend that, if they do feel depressed or experience a low mood that is unusual for them, they go and see a health professional," Deave suggested.
"I would like to reassure parents," Deave added, "that there is a lot that they themselves can do to promote their child's development even if there is depression in the family. This can be through close parent-child interactions and, for example, stimulating and fun play."