首页
登录
职称英语
In the 24 years since the birth of Louise Brown, the world’s first test-tube
In the 24 years since the birth of Louise Brown, the world’s first test-tube
游客
2024-05-03
19
管理
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. [br] What is the main idea of the passage?
选项
A、Whether assisted reproductive technologies damage babies’ genes.
B、Whether test-tube technique is safe and applicable.
C、The controversy is caused by test-tube technique.
D、The studies compared ART babies with normally conceived ones.
答案
A
解析
主旨大意题。文章开头即点明,试管婴儿的数量不断增多,主要是因为科学家保证试管婴儿没有什么基因风险。接下来两段也是围绕“试管婴儿是否会比正常受孕的婴儿面临更多的风险”展开,因此答案为A)。
转载请注明原文地址:https://tihaiku.com/zcyy/3582550.html
相关试题推荐
Inthe24yearssincethebirthofLouiseBrown,theworld’sfirsttest-tube
Inthe24yearssincethebirthofLouiseBrown,theworld’sfirsttest-tube
Inthe24yearssincethebirthofLouiseBrown,theworld’sfirsttest-tube
Inthe24yearssincethebirthofLouiseBrown,theworld’sfirsttest-tube
Inthe24yearssincethebirthofLouiseBrown,theworld’sfirsttest-tube
[originaltext]M:Hey,Louise,I’vegotausedcopyofourchemistrytextbookfo
随机试题
Unlikemostsports,whichevolvedovertimefromstreetgames,basketballwa
Whatisthemaintopicoftheconversation?[br][originaltext]W:Today’sarts
Whenthewholeareawas______bytheflood,thegovernmentsentfoodtherebyh
Forwelloveracentury,onestreetinNewYorkCityhasbeenknownforthe
据相关资料显示,到去年年底,中国智能手机市场已成为全球智能手机出货量(shipment)第一的市场。Accordingtorelateddata,by
并联电路时,各电阻上的电流与电导成正比。()
商业银行可以根据银行信贷行业投向政策,对不同行业分别授予不同权限的信贷授权。(
干酪性肺炎多见A.黄色痰 B.红色痰 C.黄绿色痰 D.铁锈色痰 E.棕
下列关于实验装置和操作的叙述正确的是()。 A.装置①可用于分离互不相溶的液
关于2009~2012年全国矿产品贸易和能源生产、消费,能够从上述资
最新回复
(
0
)