Datasheet1_Maternal pre-pregnancy obesity affects the uncinate fasciculus white matter tract in preterm infants.docx

BackgroundA growing body of evidence suggests an association between a higher maternal pre-pregnancy body mass index (BMI) and adverse long-term neurodevelopmental outcomes for their offspring. Despite recent attention to the effects of maternal obesity on fetal and neonatal brain development, changes in the brain microstructure of preterm infants born to mothers with pre-pregnancy obesity are still not well understood. This study aimed to detect the changes in the brain microstructure of obese mothers in pre-pregnancy and their offspring born as preterm infants using diffusion tensor imaging (DTI).
MethodsA total of 32 preterm infants (born to 16 mothers with normal BMI and 16 mothers with a high BMI) at <32 weeks of gestation without brain injury underwent brain magnetic resonance imaging at term-equivalent age (TEA). The BMI of all pregnant women was measured within approximately 12 weeks before pregnancy or the first 2 weeks of gestation. We analyzed the brain volume using a morphologically adaptive neonatal tissue segmentation toolbox and calculated the major white matter (WM) tracts using probabilistic maps of the Johns Hopkins University neonatal atlas. We investigated the differences in brain volume and WM microstructure between preterm infants of mothers with normal and high BMI. The DTI parameters were compared among groups using analysis of covariance adjusted for postmenstrual age at scan and multiple comparisons.
ResultsPreterm infants born to mothers with a high BMI showed significantly increased cortical gray matter volume (p = 0.001) and decreased WM volume (p = 0.003) after controlling for postmenstrual age and multiple comparisons. We found a significantly lower axial diffusivity in the uncinate fasciculus (UNC) in mothers with high BMI than that in mothers with normal BMI (1.690 ± 0.066 vs. 1.762 ± 0.101, respectively; p = 0.005).
ConclusionOur study is the first to demonstrate that maternal obesity impacts perinatal brain development patterns in preterm infants at TEA, even in the absence of apparent brain injury. These findings provide evidence for the detrimental effects of maternal obesity on brain developmental trajectories in offspring and suggest potential neurodevelopmental outcomes based on an altered UNC WM microstructure, which is known to be critical for language and social–emotional functions.

研究背景：越来越多的证据表明，孕前母亲较高的体重指数（Body Mass Index, BMI）与其子代不良的长期神经发育结局存在关联。尽管近期学界对母亲肥胖对胎儿及新生儿脑发育的影响给予了广泛关注，但孕前肥胖母亲所生早产儿的脑微观结构变化仍未得到充分阐明。本研究旨在借助弥散张量成像（Diffusion Tensor Imaging, DTI），探究孕前肥胖母亲所生早产儿的脑微观结构变化。

研究方法：本研究纳入32例胎龄小于32周且无颅脑损伤的早产儿，其母亲包括16名孕前体重指数正常者与16名孕前体重指数偏高者，所有受试者均在校正胎龄（Term-Equivalent Age, TEA）时接受颅脑磁共振成像检查。所有孕妇的体重指数均于孕前约12周内或妊娠前2周内完成测量。本研究采用形态学自适应新生儿组织分割工具箱分析脑容积，并借助约翰·霍普金斯大学新生儿图谱的概率图谱计算主要白质（White Matter, WM）纤维束。我们对比了孕前体重指数正常与偏高母亲所生早产儿的脑容积及白质微观结构差异。在以扫描时的经后胎龄校正协变量并校正多重比较后，采用协方差分析对各组的DTI参数进行比较。

研究结果：在校正经后胎龄与多重比较后，孕前体重指数偏高母亲所生早产儿的大脑皮层灰质容积显著升高（p=0.001），而白质容积则显著降低（p=0.003）。本研究发现，与体重指数正常母亲所生早产儿相比，体重指数偏高母亲所生早产儿的钩束（Uncinate Fasciculus, UNC）轴向弥散系数显著更低（分别为1.690±0.066与1.762±0.101；p=0.005）。

结论：本研究首次证实，即使无明显颅脑损伤，母亲孕前肥胖仍会影响校正胎龄时早产儿的围产期脑发育模式。本研究结果为母亲肥胖对子代脑发育轨迹的有害影响提供了证据，并提示钩束白质微观结构改变可能与子代的神经发育结局相关——而钩束对于语言及社会情感功能至关重要。