Pregnant women shouldn’t drink. It’s become gospel, because of the danger of fetal alcohol spectrum disorder. Alcohol can disturb the normal development of a fetus, leading to a lifetime of learning disabilities and social problems. But the percentage of children born with the disorder has remained ___1___, despite the warnings. And not all fetuses of drinking mothers suffer.

Now research with rats has shown why some fetuses are naturally protected. Which could lead to ways to ___2___. The work is in the FASEB Journal. [Laura Sitting et al., "Strain-specific vulnerability to alcohol exposure in utero via hippocampal parent-of-origin expression of deiodinase-III"]

The key is a gene called Dio3, which governs the levels of thyroid hormone in the brain. If mom ___3___ a normal Dio3, no problem. And a male fetus that inherits a problem Dio3 variation from mom but a normal Dio3 from dad should be okay. But alcohol can stop dad’s normal Dio3 gene from working. Now mom’s bad Dio3 allows the brain to ___4___ thyroid hormone, damaging the hippocampus.

The hope is that gene screening could ID women whose fetuses would be at-risk, and that dietary supplements or drugs could block alcohol’s effect. And keep a child from suffering from a parent’s ___5___.
【视听版科学小组荣誉出品】
constant protect the vulnerable ones passes on be flooded with addiction
准妈妈，莫饮酒。这已经成为人人传诵的真理了，因为担心怀孕妈妈饮酒会导致胎儿酒精谱系障碍。酒精会阻碍胎儿的正常发育，导致孩子终生学习能力障碍以及社交障碍。尽管人们向准妈妈们屡屡敲响警钟，但酒精综合症胎儿的出生比率仍未下降。不过，也不是所有酗酒的妈妈生出来的孩子都会得这种病。 研究人员对小老鼠进行了实验并发现了某些酗酒妈妈的胎儿不患病的原因，这项发现也许能够为容易患病的胎儿提供保护措施。该研究成果刊登在《美国实验生物学学会联合会期刊》上。 控制大脑中甲状腺激素水平的Dio3基因是关键所在。假如胎儿从母方遗传到正常的Dio3基因，那就不会患病。男性胎儿从母方遗传到异常Dio3基因变体，但从父方遗传到正常Dio3基因，也不会患病。但是酒精会阻碍来自父方的正常Dio3基因作用，这样一来，母方异常Dio3基因就会引起大脑中甲状腺激素水平过高，导致大脑中海马状突起受损。 不过好在基因筛检能够检测出哪些妈妈怀孕有风险，膳食补充以及某些药物也能够阻碍酒精作用，下一代也就不必为上一代酗酒背债了。