据预测，在气候变化的极端高温下，婴儿会出生得更早

据预测，在气候变化的极端高温下，婴儿会出生得更早

When it comes to pregnancy and babies, the closer to full-term the better. Compared to full-term pregnancies, we know that near-term babies have a higher risk of medical problems soon after birth, and lower cognitive outcomes later in childhood.

说到怀孕和婴儿，越接近足月越好。与足月妊娠相比，我们知道，早产婴儿在出生后很快就有更高的发生医学问题的风险，而在儿童后期的认知结果则更低。

So, with that in mind, we have some bad news. Researchers have found that extreme heat makes babies rush to the exit sooner, leading to an average of 25,000 US infants a year born a little early due to hot weather.

所以，考虑到这一点，我们有一些坏消息。研究人员发现，极端高温会使婴儿更快地离开妈妈，导致每年平均有25000名婴儿因天气炎热而提早出生。

And like nearly everything else in this world, it's only going to get worse with climate change.

就像这个世界上几乎所有的事情一样，气候变化只会使情况变得更糟。

"Given recent increases in the frequency of extremely hot weather, there is a clear need to better forecast the potential magnitude of climate change's impact on infant health at the national level," the team explains in their paper.

研究小组在论文中解释说：“鉴于最近极端高温天气的频率增加，显然需要更好地预测气候变化对国家一级婴儿健康的潜在影响程度。”。

"We find that extreme heat causes an increase in deliveries on the day of exposure and on the following day and show that the additional births were accelerated by up to two weeks."

“我们发现，极端高温会导致暴露当天和第二天分娩量增加，并显示额外分娩的速度加快了两周。”

The two researchers - economists Alan Barreca from the University of California, Los Angeles and Jessamyn Schaller from Cambridge - used US birth rates and temperature data between 1969 and 1988 to get a handle on just how many extra babies were being born on hot days.

这两位研究人员——加州大学洛杉矶分校的经济学家艾伦·巴雷卡和剑桥大学的杰西曼·夏勒——利用美国1969年至1988年间的出生率和气温数据，来了解在炎热的天气里多生了多少婴儿。

Although past studies have looked at this from the view of gestational length, the researchers explain this can be affected by misreporting and can lead to less accurate results.

尽管过去的研究都是从孕长的角度来看待这一点，但研究人员解释说，这可能会受到误报的影响，并可能导致不太准确的结果。

Instead, the team looked at daily birth rates across the whole of the US, including a whopping 56 million births in their data.

相反，该研究小组研究了美国全境的每日出生率，数据中包括高达5600万的出生率。

"We advance the methodology of temperature–gestation studies by using data on daily birth rates, as opposed to recorded gestational lengths," the team explain.

研究小组解释说：“我们通过使用每日出生率的数据，而不是记录的妊娠期长度，来推进温度-妊娠研究的方法。”。

This works by analysing the data for a spike in births on hot days, and then checking if there is a subsequent decrease afterwards.

这项工作的原理是，分析高温天出生高峰的数据，然后检查随后是否有下降。

"For example, in a given county of the United States, an increase in birth rates on the day of hot weather followed by a decrease two days later suggests temperature reduced gestational lengths by two days."

例如，在美国的一个县，天气炎热时出生率上升，两天后出生率下降，说明温度使妊娠期缩短了两天。

They estimate that in the US, this led to 25,000 babies a year that were born a little earlier than scheduled due to heat exposure, creating a total loss of over 150,000 gestational days annually.

他们估计，在美国，这导致每年有25000名婴儿因热暴露而比预定时间稍早出生，每年造成超过150000个妊娠日的总损失。

Although a couple of days less gestation time isn't an issue for every baby, shorter gestation times have been linked to lower health and cognitive outcomes, and giving babies the best start in life means we should probably be trying to keep them a little cooler.

虽然对每个婴儿来说，缩短几天的怀孕时间并不是一个问题，但缩短怀孕时间与降低健康和认知能力有关，给婴儿最好的人生开端意味着我们应该尽量让他们保持凉爽。

We know that our climate is heating up, and without serious action, it's going to get worse. This means more hurricanes, wildfires, and heatwaves.

我们知道我们的气候正在变暖，如果不采取认真的行动，情况会变得更糟。这意味着更多的飓风、野火和热浪。

What this study shows is that it's not just the humans who have already been born that will be feeling the negative effects of the mercury rising.

这项研究表明，不仅仅是已经出生的人类会感受到水银上升的负面影响。

"At the end of the century (2080–2099), we estimate that there will be approximately 253,000 additional lost days of gestation per year on average in the United States, affecting nearly 42,000 additional births," the team write.

“在本世纪末(2080—2099)，我们估计在美国平均每年会有大约253000天的妊娠损失，影响近42000的额外分娩。”研究小组写道。

The paper has been published in Nature Climate Change.

这篇论文发表在《自然气候变化》杂志上。