A history of previous childbirths is linked to women’s white matter brain age in midlife and older age

Abstract

Maternal brain adaptations occur in response to pregnancy, but little is known about how parity impacts white matter (WM) microstructure and WM ageing trajectories later in life. Utilising global and regional brain-age prediction based on multi-shell diffusion MRI data, we investigated the association between previous childbirths and WM brain age in 8,895 women in the UK Biobank cohort (age range = 54 - 81 years). The results showed that a higher number of previous childbirths was associated with lower WM brain age, in line with previous studies showing less evident grey matter (GM) brain ageing in parous relative to nulliparous women. Both global WM and GM brain age estimates showed unique contributions to the association with previous childbirths, suggesting partly independent processes. Corpus callosum contributed uniquely to the global WM association with previous childbirths, and showed a stronger relationship relative to several other tracts. While our findings demonstrate a link between reproductive history and brain WM characteristics later in life, longitudinal studies are required to understand how parity influences women’s WM trajectories across the lifespan.

Sex- and age-specific associations between cardiometabolic risk and white matter brain age in the UK Biobank cohort

“…and WMTI [85] as input features in the age prediction models, as described in [75]. The metrics for each model are listed in Supplementary Information (SI) section 1.…”

“…The metrics for each model are listed in Supplementary Information (SI) section 1. The metrics were extracted based on subject-specific skeletonized images [100], and Johns Hopkins University (JHU) atlases for white matter tracts (with 0 thresholding) [101] were used to provide global mean values and regional measures for 12 tracts used in previous aging and development studies [75,86,87,88]; anterior thalamic radiation, corticospinal tract, cingulate gyrus, cingulum hippocampus, forceps major, forceps minor, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, uncinate fasciculus, superior longitudinal fasciculus temporal, and corpus callosum. The included diffusion MRI data passed Tract-based spatial statistics (TBSS) post-processing quality control using the YTTRIUM algorithm [102], and were residualized with respect to scanning site using linear models.…”

“…Positive BAG values have also been associated with negative outcomes in population-based studies, including cardiovascular risk, cognitive impairments, and dementia risk [59,61,62,63,68,69,70,71]. Previous studies have shown accurate age prediction based on diffusion-weighted imaging measures [72,73,74,75], as well as associations between WM BAG and CMRs [1,76]. However, these previous studies did not assess sex-specific effects, or whether CMRs interact with APOE genotype to influence WM BAG during certain life phases.…”

Sex‐ and age‐specific associations between cardiometabolic risk and white matter brain age in the UK Biobank cohort

“…Positive BAG values have also been associated with negative outcomes in population-based studies, including cardiovascular risk, cognitive impairments, and dementia risk (Biondo et al, 2021;de Lange, Anatürk, et al, 2020;Egorova et al, 2019;Franke & Gaser, 2012;Gaser et al, 2013;Kolbeinsson et al, 2020;Löwe et al, 2016;Wang et al, 2019). Previous studies have shown accurate age prediction based on diffusion-weighted imaging measures Cole, 2020;Richard et al, 2018;Voldsbekk et al, 2021), as well as associations between WM BAG and CMRs . However, these previous studies did not assess sex-specific effects, or whether CMRs interact with APOE genotype to influence WM BAG during certain life phases.…”

Evidence of subjective, but not objective, cognitive deficit in new mothers at one-year postpartum

“…Studies of cognition in rodents suggest that previous reproductive experience confers cognitive benefits which are long-lasting, perhaps even permanent 3,55 . In humans, reproductive experience is associated with life-long changes to brain structure 37,[56][57][58][59] and function 36 , and improved cognition, including verbal memory 37,59 . Verbal memory also improves longitudinally across the postpartum period (3-12 months), with postpartum mothers showing more evidence of semantic clustering (recalling related words together) than when they were pregnant 16 .…”