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___.
【視聽版科學(xué)小組榮譽出品】
constant protect the vulnerable ones passes on be flooded with addiction
準(zhǔn)媽媽，莫飲酒。這已經(jīng)成為人人傳誦的真理了，因為擔(dān)心懷孕媽媽飲酒會導(dǎo)致胎兒酒精譜系障礙。酒精會阻礙胎兒的正常發(fā)育，導(dǎo)致孩子終生學(xué)習(xí)能力障礙以及社交障礙。盡管人們向準(zhǔn)媽媽們屢屢敲響警鐘，但酒精綜合癥胎兒的出生比率仍未下降。不過，也不是所有酗酒的媽媽生出來的孩子都會得這種病。 研究人員對小老鼠進(jìn)行了實驗并發(fā)現(xiàn)了某些酗酒媽媽的胎兒不患病的原因，這項發(fā)現(xiàn)也許能夠為容易患病的胎兒提供保護(hù)措施。該研究成果刊登在《美國實驗生物學(xué)學(xué)會聯(lián)合會期刊》上。 控制大腦中甲狀腺激素水平的Dio3基因是關(guān)鍵所在。假如胎兒從母方遺傳到正常的Dio3基因，那就不會患病。男性胎兒從母方遺傳到異常Dio3基因變體，但從父方遺傳到正常Dio3基因，也不會患病。但是酒精會阻礙來自父方的正常Dio3基因作用，這樣一來，母方異常Dio3基因就會引起大腦中甲狀腺激素水平過高，導(dǎo)致大腦中海馬狀突起受損。 不過好在基因篩檢能夠檢測出哪些媽媽懷孕有風(fēng)險，膳食補充以及某些藥物也能夠阻礙酒精作用，下一代也就不必為上一代酗酒背債了。