Air Pollution Is Linked to Miscarriages in China, Study Finds

“There has been a lot of evidence suggesting a link between air pollution and pregnancy outcomes in general, particularly the risk of a premature birth and a low weight baby,” said Tom Clemens, a lecturer at the University of Edinburgh who has researched the subject and was not involved in the study. “This is one of the first studies to link particle pollution to this particular outcome of pregnancy so in that sense it’s very important.”

Health concerns about air pollution have grown rapidly in China over the past decade. One recent study suggested a link between air pollution and cognitive decline. Others have shown that China’s air pollution accounts for as many as one million premature deaths a year.

Much of the anxiety has focused on children. Chai Jing, a former reporter for the Chinese state news media, once said she was motivated to make a documentary about the country’s devastating air pollution after she had complications during a pregnancy. After its release in 2015, the documentary, “Under the Dome,” quickly went viral before Chinese Communist Party censors abruptly ordered its removal from online platforms.

The public’s fears surrounding air pollution — and the implicit threat to broader social stability — have pushed government officials to try and address the issue. Those efforts, including limiting the construction of coal-fired power plants and capping the number of cars on the road, have largely succeeded. A report released last month by the Swiss firm IQAir AirVisual said that Beijing was on track this year to drop off the list of the world’s 200 most polluted cities.

But the problem persists. Earlier this month, a pale gray haze formed the backdrop to the all-important celebrations in Beijing marking the 70th anniversary of the founding of the People’s Republic of China, despite the government’s best efforts to rein in pollution. Footage of the parade showed Chinese military aircraft streaking multicolored smoke trails across grimy skies.

In the Nature Sustainability paper, the researchers said that since 2013, the risk of missed miscarriages in the first trimester had declined along with the decrease in air pollutant concentration — further evidence, they said, of the link between the two.

They concluded their paper by framing the issue in the context of another official priority: China’s declining birthrate. Alarmed by the prospect of a shrinking work force, the government has in recent years encouraged women to have more babies, in part by easing one-child policy restrictions. But those efforts so far haven’t done much to change the trend.

“China is an aging society and our study provides an additional motivation for the country to reduce ambient air pollution for the sake of enhancing the birthrate,” the researchers wrote.

Zoe Mou contributed research.