Associations between prenatal alcohol and tobacco exposure and cortical and subcortical brain measures in South African children: a pilot study

Abstract

ObjectiveThe aim of this pilot study was to assess associations of prenatal alcohol exposure (PAE), prenatal tobacco exposure (PTE), and their interaction and quantity on subsequent cortical and subcortical measures at age 6 years.MethodsMothers with varying levels and timing of alcohol and tobacco exposures in pregnancy were approached when their children (born participating in the Safe Passage Study) were approximately 6 years old. 72 mothers agreed to participate, and 51 children completed brain magnetic resonance imaging (MRI). Linear regression was used to identify associations between PAE, PTE, and their interaction with cortical (n = 68 ROIs) and subcortical (n = 40 ROIs) measures. Brain regions of interest, that were significantly associated prior to multiple comparison testing, were examined for associations related to exposure quantity, frequency, and timing (QFT), to explore how patterns of PAE and PTE influence brain outcomes in children.ResultsPrior to correction for multiple comparison testing, both PAE and PTE, as well as their interaction, were associated with a range of cortical and subcortical measures. However, none of these findings survived correction for multiple comparisons. Nevertheless, when exploring quantity of PAE, the total amount of standard drinks consumed during pregnancy and the average number of drinks per drinking day were individually and positively associated with cortical volume in the right fusiform gyrus.ConclusionThese trend results in this pilot study provide preliminary evidence that PAE impacts brain development in unique ways from PTE, and their interactive co-exposure is not a straight forward synergistic or additive effect on the brain.

The impact of prenatal alcohol and/or tobacco exposure on brain structure in a large sample of children from a South African birth cohort

“…Despite similarities between the exposed and control participants on extreme environmental adversity (described below), these results suggest that the MTL may be more vulnerable to PAE than other brain structures are, in comparison to previous studies of PAE in the same geographical region of South Africa. Abnormalities of MTL structures have been previously reported in PAE (Moore & Xia, 2021), and neuroimaging analyses of 51 6‐year‐olds from the PASS cohort also revealed structural differences in the fusiform gyrus given PAE (i.e., another structure that spans the MTL; Uban et al, 2022). Other cortical regions affected by PAE included precentral sulcus and medial occipital cortices as well as the caudate nucleus subcortically, but these effects did not survive correction for multiple comparisons.…”

“…reported in PAE (Moore & Xia, 2021), and neuroimaging analyses of 51 6-year-olds from the PASS cohort also revealed structural differences in the fusiform gyrus given PAE (i.e., another structure that spans the MTL; Uban et al, 2022). Other cortical regions affected by PAE included precentral sulcus and medial occipital cortices as well as the caudate nucleus subcortically, but these effects did not survive correction for multiple comparisons.…”

“…Between 2007 and 2015, the PASS study recruited 7060 pregnant women during their first prenatal visit at obstetrical clinics in Cape Town, South Africa; during pregnancy, they reported their drinking and smoking behavior throughout all trimesters (Dukes et al, 2014), thus permitting assessment across a range of alcohol drinking behaviors and quantities consumed, as well as in measures of PTE quantity. Previous neuroimaging analyses of 6‐year‐old children from the PASS cohort revealed structural differences (after statistical correction) only in the right fusiform gyrus given PAE (Uban et al, 2022), potentially suggesting that any neuroanatomical effects of varying levels of PAE (or PTE) may have not yet emerged at this age. Accordingly, the aim of this study was to evaluate how PAE and PTE relate to brain development during early adolescence, which is a critical developmental period (i.e., when experience‐dependent brain plasticity is undergoing changes that impact the brain's structure and function; Laube et al, 2020).…”