MRC Nutrition and Bone Health Research Group, University of Cambridge, Cambridge, UK.
MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, UK.
J Bone Miner Res. 2020 Jul;35(7):1253-1262. doi: 10.1002/jbmr.3998. Epub 2020 Apr 8.
At birth, the neonatal skeleton contains 20 to 30 g calcium (Ca). It is hypothesized maternal bone mineral may be mobilized to support fetal skeletal development, although evidence of pregnancy-induced mineral mobilization is limited. We recruited healthy pregnant (n = 53) and non-pregnant non-lactating (NPNL; n = 37) women aged 30 to 45 years (mean age 35.4 ± 3.8 years) and obtained peripheral quantitative computed tomography (pQCT) and high-resolution pQCT (HR-pQCT) scans from the tibia and radius at 14 to 16 and 34 to 36 weeks of pregnancy, with a similar scan interval for NPNL. Multiple linear regression models were used to assess group differences in change between baseline and follow-up; differences are expressed as standard deviation scores (SDS) ± SEM. Decreases in volumetric bone mineral density (vBMD) outcomes were found in both groups; however, pregnancy-related decreases for pQCT total and trabecular vBMD were -0.65 ± 0.22 SDS and -0.50 ± 0.23 SDS greater (p < .05). HR-pQCT total and cortical vBMD decreased compared with NPNL by -0.49 ± 0.24 SDS and -0.67 ± 0.23 SDS, respectively; trabecular vBMD decreased in both groups to a similar magnitude. Pregnancy-related changes in bone microarchitecture significantly exceeded NPNL change for trabecular number (0.47 ± 0.23 SDS), trabecular separation (-0.54 ± 0.24 SDS), cortical thickness (-1.01 ± 0.21 SDS), and cortical perimeter (0.78 ± 0.23 SDS). At the proximal radius, cortical vBMD and endosteal circumference increased by 0.50 ± 0.23 SDS and 0.46 ± 0.23 SDS, respectively, compared with NPNL, whereas cortical thickness decreased -0.50 ± 0.22 SDS. Pregnancy-related decreases in total and compartment-specific vBMD exceed age-related change at the distal tibia. Changes at the radius were only evident with pQCT at the cortical-rich proximal site and suggest endosteal resorption. Although the magnitude of these pregnancy-related changes in the appendicular skeleton are small, if they reflect global changes across the skeleton at large, they may contribute substantially to the Ca requirements of the fetus. © 2020 Crown copyright. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.
在出生时，新生儿骨骼含有 20 至 30 克钙（Ca）。据推测，母体的骨矿物质可能会被动员起来以支持胎儿骨骼发育，尽管妊娠引起的矿物质动员的证据有限。我们招募了健康的孕妇（n=53）和非孕期非哺乳期（NPNL；n=37）年龄在 30 至 45 岁（平均年龄 35.4±3.8 岁）的女性，并在 14 至 16 周和 34 至 36 周妊娠时获得了胫骨和桡骨的外周定量计算机断层扫描（pQCT）和高分辨率 pQCT（HR-pQCT）扫描，NPNL 的扫描间隔相似。使用多元线性回归模型评估组间基线和随访之间变化的差异；差异表示为标准偏差分数（SDS）±SEM。两组的体积骨密度（vBMD）结果均下降；然而，pQCT 总骨和小梁 vBMD 的妊娠相关性下降分别为-0.65±0.22 SDS 和-0.50±0.23 SDS（p<0.05）。与 NPNL 相比，HR-pQCT 总骨和皮质骨密度分别降低了-0.49±0.24 SDS 和-0.67±0.23 SDS；两组的小梁骨密度均下降。与 NPNL 相比，骨小梁数量（0.47±0.23 SDS）、骨小梁分离（-0.54±0.24 SDS）、皮质厚度（-1.01±0.21 SDS）和皮质周长（0.78±0.23 SDS）的妊娠相关骨微结构变化显著增加。与 NPNL 相比，桡骨近端的皮质骨密度和内骨周长分别增加了 0.50±0.23 SDS 和 0.46±0.23 SDS，而皮质厚度则降低了-0.50±0.22 SDS。与 NPNL 相比，胫骨远端的总骨和腔室特异性 vBMD 均呈妊娠相关性下降。桡骨的变化仅在皮质丰富的近端部位用 pQCT 检测到，表明内骨吸收。尽管这些妊娠相关变化在附肢骨骼中的幅度较小，但如果它们反映了整个骨骼的广泛变化，它们可能会大大增加胎儿对 Ca 的需求。© 2020 英国版权所有。《骨与矿物质研究杂志》由 Wiley 期刊 LLC 代表美国骨与矿物质研究协会（ASBMR）出版。本文经英国王室专利局和苏格兰皇家印务局许可出版。
