Periconceptual and prenatal alcohol consumption and neurodevelopment at age two and five years

Maternal perinatal depression and child neurocognitive development: A relationship still to be clarified

Pregnancy frequently is associated with emotional conditions such as anxiety and depression. Perinatal depression has an incidence of around 12%. Only recently researcher put the attention on the effects of pre- and postpartum psychopathology on infant neurocognitive development. Neurobiology studies indicate that perinatal maternal depression can significantly affect the structure and function of children's prefrontal cortex and modulate the development of cognitive abilities from intrauterine life. On the topic, the scientific literature appears ambiguous, reporting mixed results. Some studies have found no significant differences in developmental outcomes between prenatal and postpartum exposure to maternal depression, others have suggested a greater burden of depression in pregnancy than in postpartum, and still others have emphasized the role of chronicity of symptoms rather than the period of onset. Few studies have examined the effects of different developmental trajectories of maternal depression on children's neurocognitive outcomes. The assessment of maternal health has for years been limited to postpartum depression often neglecting the timing of onset, the intensity of symptoms and their chronicity. These aspects have received less attention than they deserve, especially in relation to the effects on children's neurocognitive development. The aim of this Perspective was to highlight inconsistencies and gaps that need to be filled in the approach to the study of this problem. Given the wide heterogeneity of data in the current literature, further studies are needed to clarify these interactions. This Perspective provides an overview of current progress, future directions, and a presentation of the authors' views on the topic.

Low to Moderate Prenatal Alcohol Exposure and Neurodevelopmental Outcomes: A Narrative Review and Methodological Considerations

PURPOSE

Although abstinence is recommended in pregnancy, many pregnancies are exposed to alcohol. Observational studies of the effects of low to moderate prenatal alcohol exposure (PAE) and neurodevelopmental outcomes have yielded inconsistent results, with some studies finding an increased risk of adverse neurobehavioral and cognitive outcomes, and other studies finding no changes or reduced risk of the same outcomes. The purpose of this narrative review is to summarize these inconsistencies and apply a methodological framework to discuss how different parameters contribute to the findings. The authors also provide recommendations on how to advance future research in this area.

SEARCH METHODS

The PubMed, Web of Science, and Embase databases were searched, along with reference lists of selected systematic reviews and meta-analyses. Search terms used were (infant or child or children or adolescent or offspring) AND (low or light or mild or moderate or low-to-moderate) AND (drinking or alcohol or drinks) AND (pregnancy or prenatal or fetal) AND (neurodevelopment or behavioral or psychological or cognitive or developmental) NOT (mice or rat or fish or animal) NOT (meta-analysis or review). Peer-reviewed original research studies were included if they analyzed associations between an exposure defined and characterized as low/light or moderate PAE with offspring neurodevelopmental outcomes. Animal studies, studies that did not provide clear cutoff points to classify PAE categories, studies lacking an abstinence control group, and studies that did not present a multivariable-adjusted measure of association were excluded.

SEARCH RESULTS

The searches identified 2,422 papers, with 36 papers meeting eligibility criteria. These studies were carried out across nine countries and included samples ranging from approximately 500 to 40,000 participants. Cognitive, academic, socioemotional, and behavioral outcomes were assessed from infancy through age 19.

DISCUSSION AND CONCLUSION

When the findings from the selected articles were summarized by geographic region, exposure definition, or neurodevelopmental outcome, no consistent observations or patterns emerged between low to moderate PAE and offspring outcomes. Although some studies found positive (i.e., beneficial) associations between low to moderate PAE and outcomes (primarily outcomes related to cognition) and others found negative (i.e., detrimental) associations (primarily for behavioral outcomes), most findings were null (i.e., showed no effect of PAE). The heterogeneity in study results is likely due to methodological issues, including residual confounding, effect measure modification, and exposure misclassification that make synthesis of studies difficult. Alternative study designs, including longitudinal trajectory analysis, sibling design, negative controls, and instrumental variable analyses, may reduce biases and are discussed. To date, the consequences of light to moderate levels of PAE on neurodevelopment remain unresolved; studies that advance methodological rigor will be important contributions to the field.