Wells Jonathan C K
MRC Childhood Nutrition Research Centre, 30 Guilford Street, London WC1N 1EH, UK.
J Theor Biol. 2002 Feb 7;214(3):413-25. doi: 10.1006/jtbi.2001.2465.
Human birth weight is known to be influenced by several factors, including maternal energy supply, maternal stature, disease status, smoking status and gestation length. This article proposes that the thermal environment may be a further factor influencing birth weight. Experimental animal studies demonstrate clear effects of thermal stress on placental function and birth weight, but may have limited relevance for humans due to between-species differences in pregnancy physiology. Observational studies suggest an inverse relationship between environmental temperature and birth weight within and between human populations. Variation in maternal size, body fatness, pregnancy weight gain and heat production is predicted to influence maternal thermoregulatory capacity, as are the size and composition of the foetus. These associations generate the hypothesis that low birth weight in hot environments may in part represent an adaptation to environmental heat stress.
众所周知，人类出生体重受多种因素影响，包括母亲的能量供应、母亲的身高、疾病状况、吸烟状况和妊娠期长度。本文提出，热环境可能是影响出生体重的另一个因素。实验动物研究表明，热应激对胎盘功能和出生体重有明显影响，但由于不同物种在妊娠生理学上存在差异，这些研究对人类的相关性可能有限。观察性研究表明，人群内部和人群之间，环境温度与出生体重呈负相关。预计母亲体型、体脂、孕期体重增加和产热的变化会影响母亲的体温调节能力，胎儿的大小和组成也会产生同样的影响。这些关联产生了一个假说，即炎热环境中的低出生体重可能部分代表了对环境热应激的一种适应。
