The couple and coparenting relationship are theorized to influence each other in a reciprocal manner over time. Empirical evidence demonstrates cross-sectional associations between the 2 as well as prospective predictions of coparenting by relationship quality and vice versa. However, less is known about the longitudinal reciprocity between the couple relationship and coparenting from the perspective of both parents. The current study sought to examine longitudinal associations between relationship quality and coparenting support/undermining across the transition to parenthood from a dyadic perspective. Participants were 164 cohabiting heterosexual couples expecting their 1st child, assessed during pregnancy and at 6 and 36 months after birth. Actor partner interdependence modeling was used to examine, for both men and women, (a) stability over time in relationship quality and coparenting, (b) reciprocal associations between relationship quality and coparenting support/undermining, and (c) the gender differences in those associations. Moderate rank-order stability in relationship quality and coparenting support/undermining across the 1st 3 years of parenthood was demonstrated. For women, but not men, findings suggested longitudinal reciprocal associations between relationship quality and coparenting support/undermining. Specifically, our findings suggested that prenatal relationship quality sets the stage for coparenting functioning after birth for both men and women but that coparenting functioning is then connected to subsequent feelings about the romantic relationship for only women. (PsycINFO Database Record

The current study examined parenting stress (disaggregated into personal distress and child rearing stress) at 12 months postpartum as a mediator of the longitudinal association between parental negative affectivity at 6 months postpartum and harsh parenting at 3 years postpartum for first-time parents with a child transitioning from late toddlerhood to the early preschool years. Analyses were conducted using Mediation for Actor Partner Interdependence Modeling in a sample of 164 couples who participated in a randomized controlled trial of a universal, couple-based transition to parenthood program. There were indirect actor effects of negative affect on a parent's own harsh parenting through both dimensions of parenting stress, with a stronger mediating effect for personal distress than child rearing stress. There were also indirect partner effects of negative affect on one's partner's harsh parenting through the partner's parenting stress, with a stronger indirect partner effect from mothers' negative affect to fathers' harsh parenting than vice versa. Specifically, the mediating effect of personal distress was found for both mothers and fathers, whereas the mediating effect of child rearing stress was found from mothers' negative affect to fathers' harsh parenting only. Findings highlight the importance of a dyadic approach in examining the longitudinal association between negative affect and harsh parenting and suggest that reducing parenting stress in the first year postpartum may decrease the risk of future harsh parenting among couples in which one or both partners experience negative affectivity. (PsycINFO Database Record