Biological mechanisms that might underlie iron's effects on fetal growth and preterm birth
Biological mechanisms that might underlie iron's effects on fetal growth and preterm birth
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DOI：
10.1093/jn/131.2.581s
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发表时间：
2001-02-01
影响因子：
4.2
通讯作者：
Allen, LH
中科院分区：
文献类型：
--
作者：
Allen, LH
大多数研究都报告了贫血与妊娠持续时间和低出生体重之间的负相关，尽管两者之间的因果联系仍有待证实。这篇文章探索了可能解释贫血、缺铁或两者兼而有之的潜在生物学机制，这些机制可能会导致低出生体重和早产。早产和宫内发育迟缓的危险因素非常相似，尽管对母亲营养状况对早产风险的影响了解相对较少。贫血或缺铁可影响妊娠结局的几种潜在的生物学机制已被确定。贫血(通过导致缺氧)和缺铁(通过增加血清去甲肾上腺素浓度)可导致母体和胎儿应激，刺激促肾上腺皮质激素释放激素(CRH)的合成。CRH浓度升高是早产、妊娠高血压综合征、子痫以及胎膜早破的主要危险因素。CRH还会增加胎儿皮质醇的生成，而皮质醇可能会抑制胎儿的纵向生长。另一种机制可能是缺铁会增加对红细胞和胎儿胎盘单位的氧化损伤。缺铁还可能增加母亲感染的风险，这会刺激CRH的产生，是早产的主要风险因素。在贫血和缺铁孕妇的随机对照补铁试验中探索这些潜在的生物学机制将是有用的。
A negative association between anemia and duration of gestation and low birth weight has been reported in the majority of studies, although a causal link remains to be proven. This paper explores potential biological mechanisms that might explain how anemia, iron deficiency or both could cause low birth weight and preterm delivery. The risk factors for preterm delivery and intrauterine growth retardation are quite similar, although relatively little is understood about the influence of maternal nutritional status on risk of preterm delivery. Several potential biological mechanisms were identified through which anemia or iron deficiency could affect pregnancy outcome. Anemia (by causing hypoxia) and iron deficiency (by increasing serum norepinephrine concentrations) can induce maternal and fetal stress, which stimulates the synthesis of corticotropin-releasing hormone (CRH). Elevated CRH concentrations are a major risk factor for preterm labor, pregnancy-induced hypertension and eclampsia, and premature rupture of the membranes. CRH also increases fetal cortisol production, and cortisol may inhibit longitudinal growth of the fetus. An alternative mechanism could be that iron deficiency increases oxidative damage to erythrocytes and the fetoplacental unit. Iron deficiency may also increase the risk of maternal infections, which can stimulate the production of CRH and are a major risk factor for preterm delivery. It would be useful to explore these potential biological mechanisms in randomized, controlled iron supplementation trials in anemic and iron-deficient pregnant women.