Effects of mothers' prenatal psychiatric status and postnatal caregiving on infant biobehavioral regulation : Can prenatal programming be modified?

The prevalence of antenatal mood and anxiety disorders and their inadequate treatment contribute to growing concerns about mental illnesses’ impact on fetal and infant development. Current research suggests that antenatal depression and anxiety are associated with alterations in physiology and behavior during infancy and beyond. Compared to infants born to non-depressed women, neonates whose mothers were depressed during pregnancy have higher cortisol levels [1], greater relative right frontal EEG activity [2], and lower vagal tone [3]. Antenatal anxiety predicts behavioral and emotional problems in preschoolers [4] and in 8–9 year–old children [5], as well as alterations in HPA axis activation among 10-year-olds [6]. Taken together, such findings support the prenatal programming hypothesis [7], which asserts that characteristics of the in utero environment, such as mood–based changes in women’s HPA–axis functioning, sculpt the uniquely plastic fetal brain, resulting in long–term maladaptive patterns of behavior and physiology [8–10]. Studies on the effects of antenatal mood and anxiety on child outcomes have controlled for the influences of postnatal depression and anxiety [5, 6]. However, there is a critical gap in our understanding with respect to the potential influence of parenting style on the relationship between antenatal diagnosis and infant physiological and behavioral outcomes. Maternal depression and anxiety have been associated with disturbances in the quality of caregiving, specifically in parental sensitivity, which is the extent to which the parent can consistently read and respond to the child’s cues. Parental sensitivity is an important aspect of caregiving and has been shown to play an integral role in adaptive self-regulatory behaviors [11, 12], and more recently, in infant fearfulness and right frontal EEG asymmetry [13, 14]. Depressed and anxious mothers tend to be less emotionally available to their children, often displaying signs of withdrawal and disinterest or behaving in an intrusive and hostile manner [15–17]. Because antenatal mood disturbance predicts postpartum depression [18, 19], and because maternal mood dysregulation has a negative effect on parenting, it is unclear the degree to which the quality of parenting may explain the infant and child outcomes that have been attributed to antenatal depression and anxiety. In the present study, we aimed to provide additional empirical support for the effect of parental sensitivity on infant physiology and behavior, and to determine how pre-and postnatal maternal factors interact to influence infant biobehavioral development. Specifically, we examined women’s antenatal diagnostic status and postnatal maternal sensitivity in relation to the following variables in 4-month–old infants: HPA–axis functioning (salivary cortisol), autonomic regulation (high frequency heart rate variability), and behavioral style (emotional responsiveness and temperament). Based on the findings of the studies described above [9, 20] [3], we expected that infants of mothers with an antenatal psychiatric diagnosis would demonstrate decreased HRV and increased baseline salivary cortisol. We also hypothesized that lower maternal sensitivity would be associated with this same pattern of infant physiology and that infants whose mothers had antenatal mood dysregulation and who were also insensitive caregivers would show the lowest HRV and highest cortisol levels. We hypothesized that infant emotional responsiveness would be attributed largely to maternal sensitivity, rather than antenatal diagnostic status, in line with the current relationship–based approach to socialization [11, 21]. We also examined an alternative hypothesis that mothers’ caregiving depends on their perception of their infant’s temperament so that infant temperament qualities “lead” the dyadic interaction, thereby eliciting different levels of maternal sensitivity and bringing about the associated influences on infant development. Specifically, we examined the hypothesis that women who describe their children as difficult are less sensitive with them.