Stillbirths, classed as such if a baby is born dead after 24 weeks of pregnancy, occur in one in every 200 births. Around 11 babies are stillborn every day in the UK, with aproximately 3,600 cases a year.

如果在孕24周之后产出死亡胎儿，就被归类为死胎，每200名孕妇中就会出现一例。英国每天都会大概11名死胎，每年将近3,600例。

Researchers have called for tighter curbs on car exhausts and industrial waste emissions to reduce the risk of air pollutants after their research concluded that exposure to ambient air pollution heightens the risk of stillbirth.

在研究者最后发现暴露在空气污染的环境之下，会增加死胎的风险，他们因此呼吁严格控制尾气排放以及工业废物的排出，以此来减轻空气污染造成的危险。

Following a review of 13 studies on the subject, published in the journal Occupational & Environmental Medicine, the researchers found the risk was particularly heightened during the third trimester of pregnancy.

之后对这一主题进行的13项研究综述，已经印刷在职业与环境医学杂志上，研究者发现这一风险在妊娠晚期特别高。

“Our results provide suggestive evidence that ambient air pollution is a risk factor for stillbirth,” they wrote.

他们写道“我们的研究结果提供的一些证据表明，外界空气污染是死胎风险的重要因素。”

“Pregnant women should be aware of the potential adverse effects of ambient air pollution, although the prevention against exposure to air pollutants generally requires more action by the government than by the individual.”

“孕妇应当意识到外界空气污染的潜在不利影响，尽管防止外界空气污染，通常只能更多地靠政府行动，还需要个人行动。”

They added: “Policies such as control of vehicular emissions, fuel quality improvement and control of industrial waste emissions should be developed and implemented to reduce the risk of air pollutants.”

他们还说“限制车辆尾气排放、提高燃油质量以及控制工业废物排出等政策应当逐步完善，并用来降低空气污染风险。”

The air pollutants linked to a heightened risk included: small particulate matter of less than 2.5 microns in diameter (PM2.5), PM10, nitrogen dioxide, sulphur dioxide, carbon monoxide and ozone.

与空气污染相关的高风险包括：大气中颗粒直径小于2.5微米(PM2.5)、PM10、二氧化氮、二氧化硫、二氧化碳以及臭氧。

But they stressed that further research is needed to strengthen the evidence.

但是他们也强调说需要进一步研究作为支撑证据。