Bekkhus M, et al. - Epidemiological studies have reported an association between prenatal exposure to maternal anxiety and child emotional difficulties. One key concern, however, is that this link is vulnerable to confounding by pleiotropic genes or environmental family factors. This current study assessed this link and offers little support for there being an independent prenatal impact on child emotional difficulties, rather data indicated that this link could be confounded by pleiotropic genes or environmental family factors.

Methods

• This study was performed using data on 82 383 mothers and children from the population-based Mother and Child Cohort Study and data on 21 980 siblings.
• Mothers filled out questionnaires for each unique pregnancy, for infant difficulties at 6 months and for emotional difficulties at 36 months.
• Using logistic regression analyses and multiple linear regression analyses for the full study sample and the sibling sample, researchers assessed the link between prenatal maternal anxiety and child difficulties.

Results

• They observed that in the conventional full-cohort analyses, prenatal exposure to maternal anxiety was associated with child difficulties at both 6 months [odds ratio (OR) = 2.1 (1.94–2.27)] and 36 months [OR = 2.72 (2.47–2.99)].
• The findings were essentially the same whether researchers examined difficulties at 6 months or at 36 months.
• However, findings demonstrated that these links were no longer present once potential social and genetic confounders were controlled in the sibling comparison analyses, either at 6 months [OR = 1.32 (0.91–1.90)] or at 36 months [OR = 1.28 (0.63–2.60)].
• Multiple regression analyses with continuous measures also provided essentially the same findings.