Julian Colleen Glyde, Wilson Megan J, Lopez Miriam, Yamashiro Henry, Tellez Wilma, Rodriguez Armando, Bigham Abigail W, Shriver Mark D, Rodriguez Carmelo, Vargas Enrique, Moore Lorna G
Altitude Research Center, Department of Surgery, University of Colorado Denver, Aurora, CO 80045-0508, USA.
Am J Physiol Regul Integr Comp Physiol. 2009 May;296(5):R1564-75. doi: 10.1152/ajpregu.90945.2008. Epub 2009 Feb 25.
The effect of high altitude on reducing birth weight is markedly less in populations of high- (e.g., Andeans) relative to low-altitude origin (e.g., Europeans). Uterine artery (UA) blood flow is greater during pregnancy in Andeans than Europeans at high altitude; however, it is not clear whether such blood flow differences play a causal role in ancestry-associated variations in fetal growth. We tested the hypothesis that greater UA blood flow contributes to the protection of fetal growth afforded by Andean ancestry by comparing UA blood flow and fetal growth throughout pregnancy in 137 Andean or European residents of low (400 m; European n = 28, Andean n = 23) or high (3,100-4,100 m; European n = 51, Andean n = 35) altitude in Bolivia. Blood flow and fetal biometry were assessed by Doppler ultrasound, and maternal ancestry was confirmed, using a panel of 100 ancestry-informative genetic markers (AIMs). At low altitude, there were no ancestry-related differences in the pregnancy-associated rise in UA blood flow, fetal biometry, or birth weight. At high altitude, Andean infants weighed 253 g more than European infants after controlling for gestational age and other known influences. UA blood flow and O(2) delivery were twofold greater at 20 wk in Andean than European women at high altitude, and were paralleled by greater fetal size. Moreover, variation in the proportion of Indigenous American ancestry among individual women was positively associated with UA diameter, blood flow, O(2) delivery, and fetal head circumference. We concluded that greater UA blood flow protects against hypoxia-associated reductions in fetal growth, consistent with the hypothesis that genetic factors enabled Andeans to achieve a greater pregnancy-associated rise in UA blood flow and O(2) delivery than European women at high altitude.
与低海拔地区（如欧洲人）起源的人群相比，高海拔地区（如安第斯人）出生体重降低的影响明显较小。在高海拔地区，安第斯孕妇孕期子宫动脉（UA）血流量高于欧洲孕妇；然而，尚不清楚这种血流量差异是否在胎儿生长的种族相关变异中起因果作用。我们通过比较137名居住在玻利维亚低海拔（400米；欧洲人n = 28，安第斯人n = 23）或高海拔（3100 - 4100米；欧洲人n = 51，安第斯人n = 35）的安第斯或欧洲居民孕期的UA血流量和胎儿生长情况，来检验以下假设：较高的UA血流量有助于保护安第斯种族胎儿的生长。通过多普勒超声评估血流量和胎儿生物测量，并使用一组100个祖先信息遗传标记（AIMs）确认母亲的种族。在低海拔地区，UA血流量、胎儿生物测量或出生体重的孕期相关增加不存在种族相关差异。在高海拔地区，在控制孕周和其他已知影响因素后，安第斯婴儿比欧洲婴儿重253克。在高海拔地区，20周时安第斯女性的UA血流量和氧气输送量是欧洲女性的两倍，同时胎儿尺寸也更大。此外，个体女性中美洲原住民血统比例的变化与UA直径、血流量、氧气输送量和胎儿头围呈正相关。我们得出结论，较高的UA血流量可防止胎儿生长因缺氧而减少，这与以下假设一致：遗传因素使安第斯女性在高海拔地区孕期UA血流量和氧气输送量的增加幅度大于欧洲女性。
