Complication risk for older mums 大龄母亲生育危险复杂化
文章来源:未知 文章作者:meng 发布时间:2009-09-16 03:09 字体: [ ]  进入论坛
(单词翻译:双击或拖选)

UK scientists have produced further evidence to suggest delaying becoming a mother may be risky1.

英国科学家发现了深层次的证据证明推迟生育可能有危险。

Older women may be more at risk of complications
Older women may be more at risk of complications

They found women who start their periods early were more likely to require medical assistance such as forceps(钳子,镊子), or a Caesarean section.

The effect was neutralised if these women had their first baby at an early age - but not for older mothers.

The University of Cambridge study features in BJOG: An International Journal of Obstetrics and Gynaecology.

The research was based on an analysis of data on 3,739 first-time mothers.

The Cambridge team found that the average age for the start of menstruation(月经) was 13.

An earlier start was more common among shorter girls and those with a higher body mass index(身体质量指数).

Just over one in four (26.9%) women who did not start their periods until at least the age of 15 required medical assistance during delivery.

But for those who started menstruation early, from the age of 12 onwards, the rate of medical assistance was closer to one in three (32.4%).

Sex hormones2

The researchers believe that the key is that women who start menstruation earlier are exposed to the sex hormones oestrogen(雌激素) and progesterone(黄体酮) for a longer time.

Both hormones are thought to impair3 the way the uterus(子宫) contracts during labour.

The theory is bolstered4(支持) by the finding that women who had their first child at an early age were not at a higher risk of requiring medical assistance during birth even if they started menstruation - known technically5 as menarche(初潮) - early.

Previous studies have also shown that the risk of a medically-assisted delivery increases with a woman's age at the time of her first birth.

Researcher Professor Gordon Smith stressed that while the age at which women started having periods showed little variation, the age at which they started a family did.

He said: "The main significance of this study is not that menarche is usefully predictive of the risk of complications, but that the current finding sheds light on why advanced maternal6(母亲的) age at the time of first birth might be associated with increased risks."

Professor Philip Steer7, BJOG editor-in-chief, said there was evidence to suggest that women were starting to menstruate at an earlier age - with rising obesity8 rates a possible factor.

He said the potentially damaging effect of too much - or too little - oestrogen on the female body was something that doctors had noticed over the years.

However, he stressed more, larger scale research was required before firm conclusions could be drawn9 about the impact of early menstruation.

Evolution

In the meantime, he said women who have had early periods should not worry.

But he added: "It is particularly important for them to ensure they lead healthy lifestyles and maintain a normal body weight, as a high BMI during pregnancy10 is itself associated with poor uterine contractions11 and an increased need for operative delivery."

Scientists suspect that a woman's body is designed to have children shortly after becoming fertile.

In evolutionary12 terms, a long gap between puberty(青春期) and childbirth was not desirable as life expectancy13 among our ancestors was short.

The early onset14 of menstruation has previously15 been linked to a raised risk of breast and womb cancer.



点击收听单词发音收听单词发音  

1 risky IXVxe     
adj.有风险的,冒险的
参考例句:
  • It may be risky but we will chance it anyhow.这可能有危险,但我们无论如何要冒一冒险。
  • He is well aware how risky this investment is.他心里对这项投资的风险十分清楚。
2 hormones hormones     
n. 荷尔蒙,激素 名词hormone的复数形式
参考例句:
  • This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
  • The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。
3 impair Ia4x2     
v.损害,损伤;削弱,减少
参考例句:
  • Loud noise can impair your hearing.巨大的噪音有损听觉。
  • It can not impair the intellectual vigor of the young.这不能磨灭青年人思想活力。
4 bolstered 8f664011b293bfe505d7464c8bed65c8     
v.支持( bolster的过去式和过去分词 );支撑;给予必要的支持;援助
参考例句:
  • He bolstered his plea with new evidence. 他举出新的证据来支持他的抗辩。 来自《现代英汉综合大词典》
  • The data must be bolstered by inferences and indirect estimates of varying degrees of reliability. 这些资料必须借助于推理及可靠程度不同的间接估计。 来自辞典例句
5 technically wqYwV     
adv.专门地,技术上地
参考例句:
  • Technically it is the most advanced equipment ever.从技术上说,这是最先进的设备。
  • The tomato is technically a fruit,although it is eaten as a vegetable.严格地说,西红柿是一种水果,尽管它是当作蔬菜吃的。
6 maternal 57Azi     
adj.母亲的,母亲般的,母系的,母方的
参考例句:
  • He is my maternal uncle.他是我舅舅。
  • The sight of the hopeless little boy aroused her maternal instincts.那个绝望的小男孩的模样唤起了她的母性。
7 steer 5u5w3     
vt.驾驶,为…操舵;引导;vi.驾驶
参考例句:
  • If you push the car, I'll steer it.如果你来推车,我就来驾车。
  • It's no use trying to steer the boy into a course of action that suits you.想说服这孩子按你的方式行事是徒劳的。
8 obesity Dv1ya     
n.肥胖,肥大
参考例句:
  • One effect of overeating may be obesity.吃得过多能导致肥胖。
  • Sugar and fat can more easily lead to obesity than some other foods.糖和脂肪比其他食物更容易导致肥胖。
9 drawn MuXzIi     
v.拖,拉,拔出;adj.憔悴的,紧张的
参考例句:
  • All the characters in the story are drawn from life.故事中的所有人物都取材于生活。
  • Her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。
10 pregnancy lPwxP     
n.怀孕,怀孕期
参考例句:
  • Early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
  • Smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。
11 contractions 322669f84f436ca5d7fcc2d36731876a     
n.收缩( contraction的名词复数 );缩减;缩略词;(分娩时)子宫收缩
参考例句:
  • Contractions are much more common in speech than in writing. 缩略词在口语里比在书写中常见得多。 来自《简明英汉词典》
  • Muscle contractions are powered by the chemical adenosine triphosphate(ATP ). 肌肉收缩是由化学物质三磷酸腺苷(ATP)提供动力的。 来自辞典例句
12 evolutionary Ctqz7m     
adj.进化的;演化的,演变的;[生]进化论的
参考例句:
  • Life has its own evolutionary process.生命有其自身的进化过程。
  • These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。
13 expectancy tlMys     
n.期望,预期,(根据概率统计求得)预期数额
参考例句:
  • Japanese people have a very high life expectancy.日本人的平均寿命非常长。
  • The atomosphere of tense expectancy sobered everyone.这种期望的紧张气氛使每个人变得严肃起来。
14 onset bICxF     
n.进攻,袭击,开始,突然开始
参考例句:
  • The drug must be taken from the onset of the infection.这种药必须在感染的最初期就开始服用。
  • Our troops withstood the onset of the enemy.我们的部队抵挡住了敌人的进攻。
15 previously bkzzzC     
adv.以前,先前(地)
参考例句:
  • The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • Let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
TAG标签: mother risk sex delay
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