咖啡将流产几率加倍 !!!

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Caffeine doubles miscarriage risk, study finds

CHICAGO (Reuters) - Pregnant women who drink two or more cups of coffee a day have twice the risk of having a miscarriage as those who avoid caffeine, U.S. researchers said on Monday.

They said the study provides strong evidence that high doses of caffeine during pregnancy -- 200 milligrams or more per day or the equivalent of two cups of coffee -- significantly increase the risk of miscarriage.

And they said the research may finally put to rest conflicting reports about the link between caffeine consumption and miscarriage.

\"Women who are pregnant or are actively seeking to become pregnant should stop drinking coffee for three months or hopefully throughout pregnancy,\" said Dr. De-Kun Li of Kaiser Permanente Division of Research, whose study appears in the American Journal of Obstetrics and Gynecology.

\"There has been a lot of uncertainty about this,\" Li said in a telephone interview. \"There was no firm advice from professional societies to say what a pregnant woman should do about caffeine intake.\"

Li said anywhere from 15 to 18 studies have found a link between caffeine use during pregnancy and miscarriage. But that association has been clouded by the fact that many pregnant women avoid caffeine because it makes them nauseated, which could skew the results.

Li and colleagues took pains to control for that possibility. Their study involved 1,063 pregnant women who were members of the Kaiser Permanente health plan in San Francisco from October 1996 through October 1998. Women in the group never changed their caffeine consumption during pregnancy.

What they found was women who consumed the equivalent of two or more cups of regular coffee or five 12-ounce cans of caffeinated soda -- were twice as likely to miscarry as pregnant women who avoided caffeine.

This risk appeared to be related to the caffeine, rather than other chemicals in coffee, because they also saw an increased risk when the caffeine was consumed in soda, tea, and hot chocolate.

Li said many researchers think caffeine is harmful because it stresses the fetus' immature metabolism. It may also decrease blood flow in the placenta, which could harm the fetus.

\"To me, the safe dose is zero,\" Li said. \"If you really have to drink coffee, try to limit it to one cup or at the most two cups.\" Or better yet, switch to decaffeinated beverages, he added.

Based on the findings, Dr. Tracy Flanagan, director of women's health at Kaiser Permanente Northern California, said pregnant women should think about limiting coffee to one cup a day, and they might want to cut it out entirely.

\"So many causes of miscarriage are not controllable,\" she said in a telephone interview. \"This is an opportunity to do something active.\"

http://www.reuters.com/article/healthNews/idUSN2034583320080121
芝加哥，路透社，美国研究人员在周一称，相比起那些不接触咖啡因的女性来说，每天饮用两杯以上咖啡的怀孕妇女发生流产的风险增加了1倍。

这项研究提供了确凿的证据，证实在孕期进食高浓度的咖啡因——大约是200mg以上或是相当于两杯咖啡的量，显著增加了流产的风险。在刊登在《美国妇产学杂志》上的报道里，研究人员建议，已经怀孕或是积极准备怀孕的女性应该停止饮用咖啡3个月，甚至是整个孕期。

关于怀孕妇女咖啡因摄入的问题，一直以来就有很多不确定的因素，没有来自于专业机构的确定的建议。但是很多怀孕的女性会因为咖啡因让她们感觉恶心停止使用，这就干扰了结果的解读。这就让研究人员费了不少周折来控制这个因素。

研究共纳入了1063名女性，她们都是在1996年10月至1998年10月开展的旧金山Kaiser Permanente健康计划的参与者。在这个研究中，参加的女性都没有在孕期改变她们的咖啡摄入习惯。结果显示，相比起不接触咖啡因的女性来说，那些每天摄入两杯以上普通咖啡或者摄入相当于5罐12盎司咖啡苏打水的女性，她们的流产风险增加至两倍。这个风险似乎是和咖啡因相关，而与咖啡中的其他化学成分无关，因为当咖啡因通过苏打水、茶或是热可可的形式被摄入的时候，这种风险也是增加的。很多研究人员认为咖啡因的坏处就在于它会对胎儿尚不成熟的代谢产生应激，而且会减少胎盘的血供、伤害胎儿。研究人员建议，最安全的剂量是一滴不沾，如果你不喝不行，就尽量控制在1杯以内，最多不超过2杯，最好的方法是改变习惯，尝试其他不含咖啡因的饮料。