首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
In the 24 years since the birth of Louise Brown, the world’s first test-tube baby, thousands of would-be parents have been assur
In the 24 years since the birth of Louise Brown, the world’s first test-tube baby, thousands of would-be parents have been assur
admin
2013-07-20
21
问题
In the 24 years since the birth of Louise Brown, the world’s first test-tube baby, thousands of would-be parents have been assured that as far as scientists knew there was no extra risk of genetic damage associated with in-vitro fertilization (试管内受精). With those assurances, test-tube births have soared from a few hundred a year in the early 1980s to tens of thousands today.
But according to a pair of reports in last week’s New England Journal of Medicine, that conventional wisdom may be wrong. In the first study, doctors in Britain and Australia found that infants conceived with both straightforward test-tube methods and a more invasive technique in which sperm is injected directly into the egg, have an 8.6% risk of major birth defects—including heart and kidney abnormalities—compared with the 4.2% rate in babies made the old-fashioned way. The second study, conducted by the US Centers for Disease Control and Prevention, reported that babies conceived through what doctors call assisted reproductive technologies (ART)have 2.6 times the risk of low or very low birth weight—a significant risk factor for heart disease and cognitive problems.
There are plenty of reasons to take both studies seriously. In the low-birth-weight study, for example, the researchers allowed for the fact that parents who use assisted reproduction tend to be older than average and to have more multiple births—twins, triplets and so on. Even when they corrected for these factors, the disparity (差异)between babies conceived through ART and those conceived normally remained. But there’s no need to panic. Independent experts are quick to point out that the reports are hardly definitive. Couples who seek reproductive help are not just older; they are also infertile. "You’re comparing two different groups of patients here," says Dr. William Schoolcraft, director of the Colorado Center for Reproductive Medicine. "You have women with the disease of infertility, and you’re comparing them with women who don’t have the disease."
Some of the same caveats apply to the birth-defects study, say experts. Here, too, earlier research had found no significant differences between test-tube babies and conventionally conceived kids. And here, again, the new study didn’t correct for the fact that women who get reproductive assistance often have something wrong with their reproductive system in the first place. Even if these new studies are borne out by later research—already under way in infertility programs in Australia and the US—the risks to kids conceived by ART remain reassuringly small. And even if the danger is twice what doctors previously believed, 91% of ART babies would still be born perfectly healthy.
What did the two reports in New England Journal of Medicine find?
选项
A、Test-tube techniques should be abandoned for ethical reasons.
B、Test-tube babies are exposed to higher risk of major birth defects.
C、ART babies tend to run the risk of low or very low birth weight.
D、Test-tube babies are prone to ailments compared with others.
答案
D
解析
推理判断题。根据第二段内容可知,第一个研究发现,这种孩子患有严重出生缺陷的风险为8.6%;第二个研究发现,这些婴儿出生体重偏低或者严重偏低的风险是正常受孕的婴儿的2.6倍。因此答案为D)。
转载请注明原文地址:https://kaotiyun.com/show/FOn7777K
0
大学英语六级
相关试题推荐
IntheUnitedStates,thefirstdaynurserywasopenedin1854.Nurserieswereestablishedinvariousareasduringthe【C1】______
IntheUnitedStates,thefirstdaynurserywasopenedin1854.Nurserieswereestablishedinvariousareasduringthe【C1】______
Halloweenusedtobesomethingquitedifferentfromthecelebrationofsugarygreedthatgoesontoday.Earlierinthiscent
Newtechnologylinkstheworldasneverbefore.Ourplanethas【B1】_____.It’snowa"globalvillage"wherecountriesareonlyse
Opponentsofbilingualeducationtellusthatthepublicisagainstbilingualeducation.Thisimpressionisaresultoftheway
A、Decideforhimselfwhatisbest.B、Communicatehiscareerhopes.C、Stophinderinghisownprogress.D、Lookforanothercareer.
1.食品安全事故屡有发生2.人们对食品的安全越来越担心3.怎样才能解决好食品的安全问题
Todefinesciencewemaysimplycallit______.Whichofthefollowingstatementsdoestheauthorimply?
OnDecember25,2000,manypeopleacrossNorthAmericareceivedarareChristmastreatwhenthemoonpassedinfrontofthesun
In2002,environmentministersfromaroundtheworldgatheredintheHagueforamajorsummitontheConventiononBiologicalDi
随机试题
A.0.70B.0.80C.0.85D.1.0长期饥饿时呼吸商接近于
体内蛋白质分解代谢的终产物是
按照药性理论。治疗水肿、脚气的药物大多具有的药味是
某患者,女,40岁,症见经期提前,量多或少,经色紫红,质稠有块,经前乳房、胸胁、少腹胀痛,烦躁易怒,口苦咽干,喜叹息。舌红,苔黄,脉弦数。请回答下列问题:针对此证,应采用的治法是
内存容量指微型计算机硬盘所能容纳信息的字节数。()
案例:在关于讲授“计算机硬件”部分知识的课堂上,刘老师对“计算机被打开之后”,将板书设计为:一种是传统板书,是纯文字提纲样式的计算机硬件组成图;另一种是多媒体板书,把组成图中的部分文字用图片代替。张老师开始进行教学设计时,使用的是传统板
提出“政权是由枪杆子中取得的”这一重要论断的是()。
事业单位的无形资产按取得途径分为()。
领导让你负责组织一次关爱困难社区的阳光活动,你如何组织?
请根据下列文字资料,回答问题:2005年我国对外贸易出口总额达到7620亿美元,占全球贸易出口总额的比重由2001年的4.3%提高到2005年的7.3%。2005年,我国对外贸易进出口总额为14221亿美元,居世界第三位,占全球贸易进出口总额的6
最新回复
(
0
)