Correlations were calculated between the log transformation of the maternal blood and urine cotinine measures (used to correct for the skewness of the cotinine distributions) and the self-report estimates of smoking (overall computed average and estimates for the Belinostat HDAC four separate time periods). Correlations between the log transformation of maternal blood cotinine at birth and self-reports of cigarettes per day were all significant (.307 �� r �� .498, ps < .001). Results were similar for the correlations between the log transformation of maternal urine cotinine at six months and the same self-reports of smoking (.416 �� r �� .610, ps < .001). Analyses of Smoking in Pregnancy and Parenting Stress Average number of cigarettes per day during pregnancy, described in detail in the ��Methods�� section, was used as the primary independent variable of interest.

The continuous measure of maternal smoking was necessary for regression and mediational analyses and allowed for the examination of dose�Cresponse relationships. Analyses by group (nonsmoking/light/heavy) were completed to provide descriptive information for the dependent and mediating measures (see Table 2). Table 2. Group Means, SDs, and Significance Tests for Parenting Stress Scales and Potential Mediating Variables (N = 218a) The PSI Total Stress Index was used as the primary dependent variable of interest. Individual stress subscales were all highly intercorrelated (.38 �� r �� .528, ps < .001); therefore, the Total Stress Index was used as the primary dependent variable of interest.

Scores were calculated as item-rating sum totals from the 36 items and ranged from 36 to 115. Two mediating variables are proposed in this study: maternal psychological symptoms and SES. For maternal psychological symptoms, all subscales from the SCL-90-R were highly intercorrelated (.434 �� r �� .805, ps < .001); therefore, the Global Severity Index was used. Scores were reported as T-scores (M = 50, SD = 10) and ranged from 30 to 81. SES, as measured by the SES-Factor score, also was hypothesized as a mediating variable and has been described in the ��Methods�� section. Basic parametric analyses were conducted to examine relationships among the variables of interest. Parenting stress (PSI Total Stress Index) was positively correlated with the average number of cigarettes per day during pregnancy, r (217) = .

18, p = .008. Examining specific stress subscales revealed that prenatal smoking was significantly associated with Parental Distress; r (218) = .223, p = .001; and Parent�CChild Dysfunctional Interaction; r (218) = .193, p = .004; but not with AV-951 the Difficult Child subscale. Parenting stress was also negatively correlated with the SES-Factor, r (217) = ?.194, p = .004, and positively correlated with maternal psychological symptoms as measured by the Global Severity Index for the SCL-90-R, r (217) = .495, p < .001.