Strengths and limitations
The main strengths of the present study were (1) the original study was a population‐based triple‐blind randomized controlled trial, which is a very robust design; (2) comprehensive data on sociodemographic, clinical and lifestyle information of the mothers were recorded; and (3) the assessment of children's behaviour was conducted comprehensively using reliable and internationally recognized tests. Although this study has clinical implications and will be helpful for future research in this area, it is important to keep in mind some limitations. The main limitation was the small sample size of the subgroups analysed because of high losses to follow‐up which, despite being common in population‐based intervention studies and even more so when prolonged follow‐up is required, could have weakened the statistical power of the analyses. In addition, unmeasured or unknown risk factors could have resulted in some residual confounding even after adjusting for known potential confounders. Therefore, drawing absolute conclusions may be premature and further research is warranted.