248, p <.001; and positively correlated with maternal psychological http://www.selleckchem.com/products/tofacitinib-cp-690550.html symptoms; r (218) = .187, p = .006. Regression analysis was conducted to examine whether maternal smoking during pregnancy predicts parenting stress at six months postpartum. Simple linear regression confirmed that maternal smoking during pregnancy predicted parenting stress (b = .35, SEb = .13, �� = .18, p = .008). The association was positive; higher smoking during pregnancy was associated with higher parenting stress at six months postpartum. It was predicted that maternal psychological symptoms (Global Severity Index of the SCL-90-R) and SES (SES-Factor) would mediate the relationship between maternal smoking during pregnancy and parenting stress at six months postpartum.

To test this hypothesis, a multiple mediation analysis was completed as described by Preacher and Hayes (2008a). This analysis provides a means for evaluating the indirect effects of two or more mediating variables simultaneously. According to these authors, the indirect effect of a specific mediator is ��conditional�� on the other mediators in the model. The significance of each mediator is evaluated in the context of the full model, including other proposed mediators. The analysis was completed using the SPSS macro developed by Preacher and Hayes (2008a, 2008b). This program uses a bootstrapping resampling strategy to evaluate significance of the model and effects of mediators; for this analysis, 5,000 bootstrap samples were used.

The model tested included prenatal tobacco use as the independent variable, total parenting stress at six months as the dependent variable, and both maternal psychological symptoms and SES as the mediating variables (see Figure 1). Coefficients indicating relationships between the independent variable, each mediating variable, and the dependent variable were computed. In addition, the total effect (sum of direct effect and mediated effects); the direct effect (effect of the independent variable minus the effects of the mediating variables); and the significance levels of total, direct, and specific indirect (mediating variables) effects were calculated. Figure 1. Results of mediational model showing associations among pregnancy smoking, the proposed mediating variables (maternal psychological symptoms and socioeconomic status), and parenting stress.

Results showed that maternal psychological symptoms AV-951 functioned as a mediator between prenatal tobacco use and parenting stress, but SES did not. The coefficient for the total effect (sum of the direct effect and the mediated or indirect effects) of prenatal tobacco use on parenting stress was significant (b = 0.3520, SE = 0.1304, t = 2.6991, p = .0075). Coefficients for relations among the independent, mediating, and dependent variables are displayed in Figure 1.