一种非常罕见的基因可以解释为什么有些女性在分娩时不需要止痛剂

一种非常罕见的基因可以解释为什么有些女性在分娩时不需要止痛剂

Women who don't need an epidural during childbirth might be carriers of a rare genetic variant that gives them a much higher threshold for pain, scientists have discovered.

科学家发现，在分娩过程中不需要硬膜外麻醉的女性可能是一种罕见的基因变异携带者，这种变异让她们的疼痛阈值更高。

Only about one in 100 women have the variant, which reduces the ability of nerve cells to send pain signals to the brain, researchers at the University of Cambridge found.

剑桥大学的研究人员发现，每100位妇女中就有1位是该基因变异者，这种变异会降低神经细胞向大脑发送疼痛信号的能力。

The gene then acts as a natural epidural, it and may explain why childbirth is a less painful experience for a small number of women.

这种基因就像一种自然的硬膜外麻醉，它也许可以解释为什么分娩对少数女性来说是一种不那么痛苦的经历。

Scientists put a group of women, all of whom gave birth without requesting pain relief, through a number of exercises to test their resistance to discomfort, including applying heat and pressure to their arms and asking them to plunge their hands into icy water.

科学家让一组妇女在没有要求止痛的情况下分娩，通过一系列练习测试她们对不适的抵抗力，包括在手臂上加热和加压，并要求她们把手伸进冰冷的水中。

When compared to another group of mothers who did require pain relief, they were shown to have a far higher threshold before they experienced pain.

与另一组需要减轻疼痛的母亲相比，她们在经历疼痛之前的阈值要高得多。

"It is unusual for women to not request gas and air, or epidural for pain relief during labor, particularly when delivering for the first time," said Dr. Michael Lee, joint lead author, in a press release.

“女性在分娩时不要求使用气体和空气(麻醉)，或硬膜外麻醉来缓解疼痛，这是不寻常的，特别是在第一次分娩时，”迈克尔·李博士在一份新闻稿中说。

"When we tested these women, it was clear their pain threshold was generally much higher than it was for other women," said Lee, a lecturer with the University of Cambridge's division of anaesthesia.

“当我们对这些女性进行测试时，很明显，她们的疼痛阈值通常比其他女性高得多，”剑桥大学麻醉科的讲师李说。

Their genetic code was then explored -- and scientists found a unique variant to one cell that was present in many of the women who didn't need assistance during childbirth.

然后科学家们对她们的遗传密码进行了研究，发现了一个细胞的独特变体，这种变体存在于许多分娩时不需要帮助的女性身上。

It involved the gene KCNG4, which helps produce protein that created a "gate," controlling the electric signal that flows along our nerve cells and into our brains.

它涉及到基因KCNG4，它帮助产生蛋白质，这种蛋白质会创造一个“门”， 控制沿着神经细胞流动的电信号进入我们的大脑。

"Sensitivity of this gatekeeper to electric signals that had the ability to open the gate and turn nerves on was reduced by the rare variant," the researchers found.

研究人员发现，“这种罕见的变异降低了“守门人”对电信号的敏感度，而电信号有能力打开大门并激活神经。”

"The genetic variant that we found in women who feel less pain during childbirth leads to a 'defect' in the formation of the switch on the nerve cells," co-author Ewan St. John Smith explained. "In fact, this defect acts like a natural epidural."

“我们在分娩时疼痛感较轻的女性身上发现的基因变异导致神经细胞开关形成的‘缺陷’，”合著者伊万·圣约翰史密斯解释道。“事实上，这种缺损就像是天然的硬膜外麻醉。”

"It means it takes a much greater signal -- in other words, stronger contractions during labor -- to switch it on," said Smith, a PhD with Cambridge's department of pharmacology. "This makes it less likely that pain signals can reach the brain."

“这意味着需要更大的信号——换句话说，分娩时更强烈的宫缩——来启动它，”剑桥大学药理学博士史密斯说。“这降低了疼痛信号到达大脑的可能性。”

Their study was published in the journal Cell Reports on Tuesday.

他们的研究发表在周二的《细胞报告》杂志上。

Another study from 2018 found that epidurals, which reduce the pain experienced during labor, were linked to a reduced risk of postpartum depression, although its authors cautioned that other factors might play a larger role.

2018年的另一项研究发现，减轻分娩过程中的疼痛的硬膜外麻醉与降低产后抑郁症风险有关，不过该研究的作者警告说，其他因素可能发挥更大的作用。

Epidurals are increasing in popularity among women in the United States, researchers at Stanford University found while collating data on millions of births over the past decade.

斯坦福大学的研究人员在整理过去十年中数百万的分娩数据时发现，硬膜外麻醉在美国女性中越来越受欢迎。