Studies in animals and humans suggest that psychological distress experienced by mothers during pregnancy is associated with later neurodevelopmental problems in their offspring. Project Ice Storm is one such study exploring the effect of prenatal maternal stress on child cognitive functioning.
In January 1998, an ice storm hit the Canadian province of Quebec and resulted in power loss for 3 million people for as long as 40 days. In June 1998, women who were pregnant during the ice storm completed several questionnaires evaluating their levels of objective stress and subjective distress (Impact of Events Scale-Revised) as a result of the storm. When their children were 5-½ years old, their cognitive functioning was assessed. The researchers found that prenatal exposure to high levels of objective stress was associated with lower cognitive and language abilities in children at 5-½ years of age.
Are There Protective Factors?
But we know that not all children are negatively affected by prenatal exposure to stress. What this means is that their might be protective factors that mitigate this risk. A recent study examined the impact of maternal psychological distress during pregnancy on cognitive functioning in preschoolers (ages 2.5 – 5 years) and examined the impact of positive parenting on cognitive functioning and its ability to act as a protective factor.
Mother-child dyads (N?=?162, mean child age?=?3.7 years) were recruited from a group of women who had previously participated in a longitudinal study of maternal mood disorders during pregnancy. Maternal distress during pregnancy was assessed throughout pregnancy. At the follow-up visit, parenting behaviors were recorded during a parent-child interaction and the children’s cognitive abilities were assessed using the Differential Ability Scales.
Maternal distress during pregnancy predicted lower cognitive abilities in children; however, this relationship was the strongest for children whose mothers exhibited low levels of positive engagement with their children. In contrast, maternal distress during pregnancy did not have any effect on cognitive function when mothers exhibited high levels of positive engagement.
While there are obviously many factors that influence cognitive functioning in children, these findings suggest that positive parental engagement can protect against the detrimental effects of maternal prenatal distress on preschoolers’ cognitive abilities.
Opportunities For Intervention
We have data to indicate that stress during pregnancy — whether it is the result of a natural disaster, exposure to violence or abuse, or anxiety or depression — may potentially lead to adverse outcomes for the mother and her unborn child. This study raises the possibility of intervention. If we are able to identify women with high levels of stress during pregnancy, would interventions used to decrease levels of stress during pregnancy –for example, mindfulness-based cognitive therapy or yoga — help to mitigate the detrimental effects of prenatal stress. Or could we intervene after pregnancy? Would interventions designed to optimize mother-infant interactions have a beneficial effect? Further research is needed to answer these important questions.
Ruta Nonacs, Md PhD
Schechter JC, Brennan PA, Smith AK, Stowe ZN, Newport DJ, Johnson KC.
J Abnorm Child Psychol. 2016 May 6. [Epub ahead of print]