dxy

一项政府大型研究得出结论，在分娩过程中监测胎儿血氧水平无助于分娩更健康的宝宝或降低剖腹产率。

胎儿监护问题一直备受争议。1970年以来，医生们常规听取胎儿心音，尽管没有确凿证据表明这有什么好处。后来人们以为，监测胎儿血氧水平可以更准确地表明哪个胎儿真正有危险。2000年，FDA有条件地同意批准了血氧监护仪，但要求在广泛应用之前，做更进一步的研究。

得克萨斯大学的医生们进行了这项研究。他们监测了美国十四所大学附属医院的5341名初次怀孕妇女的胎儿血氧水平。破水后，将探头伸入孕妇子宫内，放置于胎儿颞部或面颊。探头即时读取胎儿血氧水平。

这些孕妇被随机分为两组。其中一组，医生们可以看到胎儿血氧水平数值，另外一组不能看到。两组的剖腹产均为26%左右。死产、感染及其他新生儿疾病的发生率也没有差别。

这一研究发表在《新英格兰医学杂志》上，是迄今为止规模最大的，也可以认为是权威性的结果。研究人员原计划纳入10000名妇女，但是大量的证据表明，这一设备根本无效，所以研究开始不久后就停止了。

得克萨斯大学西南医学中心的妇产科主任Steven Bloom博士说：“根本没有理由用这些监护仪。我们倒没有发现它有什么害处，但为什么要把大量宝贵的卫生保健费用浪费在这些没用的东西上呢？”血氧监护仪一台10000美元，探头一个150美元。

在相关评论中，马萨诸塞州综合医院Michael Greene博士指出，这种昂贵的仪器在广泛使用之前就可以被叫停了，胎儿血氧监测不是常规护理的一部分。他说，妖怪还没有从瓶子里逃出来。

实际上，Nellcor公司发言人Kristin Garvin称，他们在获得FDA批准销售血氧监护仪OxiFirst后，因为没有订单，今年早些时候已经停止销售这种仪器了。不能确定在美国有多少家医院安装了胎儿血氧监护仪，估计已有超过400台监护仪用于约9000名美国胎儿的分娩过程监测。

FDA在一项声明中说，他们正在重新审查这项研究，有可能修改监护仪标签，或者将研究结果通知各医院。但他们称不会单纯因为这一研究就撤回对OxiFirst的批准。

http://www.***.com/2006/HEALTH/11/22/fetal.monitors.ap/
Study: Fetal oxygen monitors don't help newborns, moms
POSTED: 5:18 p.m. EST, November 22, 2006
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A large government study has concluded that monitoring fetal oxygen levels during labor does not lead to healthier newborns or reduce unnecessary Caesarean deliveries.

Fetal monitoring has long been controversial. Since the 1970s, doctors have routinely listened to fetal heartbeats despite no real evidence that it did any good. In fact, some research found that it increased the number of C-sections by making doctors nervously reach for a scalpel whenever the monitor showed an abnormal blip.

New technology that measures oxygen levels in the blood of a fetus was thought to offer a better way to tell which babies were truly at risk. In 2000, the Food and Drug Administration conditionally approved one such device, but required further study before allowing it into general use.

The study, published in Thursday's New England Journal of Medicine, was the biggest to date, involving more than 5,000 women, and was meant to be the definitive word. It was halted early because of overwhelming evidence that the technology was ineffective.

"There's no reason to use it," said lead author Dr. Steven Bloom, chief of obstetrics and gynecology at the University of Texas Southwestern Medical Center. "We didn't find any evidence of harm, but why should we invest valuable health care dollars in something that doesn't have a proven benefit?"

In an accompanying editorial, Dr. Michael Greene of Massachusetts General Hospital, who had no role in the research, noted that for once, an expensive technology can be stopped before it finds its way into widespread use. Fetal oxygen monitors are not part of routine care.

"This genie has not yet escaped from the bottle," he wrote.

In fact, Pleasanton, California-based Nellcor, which received FDA approval to market its OxiFirst devices, stopped selling them earlier this year because of a lack of demand, said company spokeswoman Kristin Garvin.

Garvin could not say how many fetal oxygen machines are installed in U.S. hospitals. In a news release 18 months after gaining FDA approval, Nellcor estimated that more than 400 devices have been used to monitor the births of about 9,000 U.S. babies.

Fetal oxygen machines are designed to be used with traditional electronic monitors, which track heart rate to determine whether the fetus is experiencing stress or lacking oxygen.

In the study, doctors monitored the fetal oxygen levels in 5,341 women pregnant for the first time at 14 university hospitals in the United States. Once a woman's water breaks, a sensor is inserted into her uterus and placed against the fetus' temple or cheek. The sensor provides an up-to-the-minute reading of the fetus' oxygen levels. (The fetal oxygen monitors cost about $10,000 each and the sensors about $150 apiece.)

The women were then randomly separated into two groups. In one group, doctors could read the oxygen levels. For the other group, the information was hidden.

In each group, about 26 percent of deliveries were done by C-section. Doctors also found no difference between the two groups in stillbirths, infections or other newborn problems.

The research was funded by the National Institute of Child Health and Human Development, part of the National Institutes of Health. Researchers had planned on enrolling 10,000 women, but the study was discontinued because no benefit was seen.

In a statement, the FDA said it was reviewing the study and may revise the label on the monitors or inform hospitals about the findings. The agency said it is unlikely it would withdraw its approval of OxiFirst based on this study alone.

Copyright 2006 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.

编辑：蓝色幻想