Sample frequencies by parental relationship and race.

<p>Sample frequencies by parental relationship and race.</p

Estimated variance components from model 2 with empirically derived 95% bootstrap confidence intervals adjusted for covariates (birth order, maternal age, fetal sex, source of care, smoking, maternal education).

<p>Estimated variance components from model 2 with empirically derived 95% bootstrap confidence intervals adjusted for covariates (birth order, maternal age, fetal sex, source of care, smoking, maternal education).</p

Expected covariance of gestational age expressed as variance components between pregnancy outcomes as a function of relationship between offspring.

<p><i>f</i>² = fetal genetic,</p><p><i>m</i>² = maternal genetic,</p><p><i>c</i>² = shared familial environment.</p><p><i>h</i> = parameter to allow for differences in half-sibling versus full-sibling shared environment.</p

Indices of model fit to assess within-group genetic and environmental contributions and between-group racial heterogeneity.

<p>The table presents the following values: −2 times the log likelihood (-2LL), the number of free parameters in the model (<i>k</i>), an index of the balance between goodness of model fit and parsimony (Akaike's information criterion, or AIC), and the <i>p</i>-value significance result from the likelihood ratio test (distributed as a chi-square statistic). The fit of model 2 was compared to model 1 and all subsequent models were compared to model 2. Significant <i>p</i>-values indicate a significant reduction in model fit. AA =  African American, EA =  European American, <i>f</i>² =  fetal effect, <i>m</i>² =  maternal effect and <i>c</i>² =  shared environmental effect.</p

MN frequencies for discordant MZ twin pairs and age-matched controls.

<p>The mean level is indicated by a horizontal bar for controls (mean [SD] 14.2 [9.4]), CSA nonexposed (14.9 [5.6]) and CSA exposed (22.0 [11.3]) twins. CSA exposure status was significant in this combined sample (<i>P</i><0.001), while there was no indication of an additional effect attributable to the familial environment (<i>P = </i>0.406) based on results from generalized mixed-effect models.</p

Relationship between MN frequency and age for CSA exposed and nonexposed twins.

<p>A significant interaction effect was observed (coefficient [SE] = 0.030 [0.009], <i>P</i> = 0.0006) with the MN level in CSA exposed twins increasing with age while the MN level remained constant across the limited age range evaluated in CSA nonexposed twins.</p

Lifestyle characteristics and adult psychiatric and substance use disorders in CSA discordant MZ twin pairs.

1<p>indicates pairs discordant for CSA and item where the exposed twin was positive for the item (n₂₁).</p>2<p>indicates pairs discordant for CSA and item where the nonexposed twin was positive for the item (n₁₂).</p>3<p>odds ratio for twin pairs doubly discordant for CSA and item (n₂₁/n₁₂).</p>4<p>prescription and non-prescription use for more than 1 year excluding birth control.</p><p>+/− ∞, value is positive/negative and infinite due to a null value in at least one category.</p>*<p>two-sided P value from exact binomial test.</p