胎兒在子宮中踢腿是因?yàn)樗残枰\(yùn)動(dòng)

The first time a pregnant woman feels her baby kick can be surprising -- a sudden reminder that the tiny creature growing inside her has a mind of its own. But why do babies kick?

孕婦第一次感受到胎兒踢腿可能會(huì)覺(jué)得很驚奇--這是突然提醒她，在她體內(nèi)生長(zhǎng)的小生命開(kāi)始有自己的想法了。但為什么胎兒會(huì)踢腿呢?

Though the womb is a tight space in which to exercise, it turns out that those kicks are vital for the baby's healthy bone and joint development, an expert told Live Science.

一名專家向《生活科學(xué)》透露，盡管子宮是一個(gè)擁擠的運(yùn)動(dòng)場(chǎng)所，但這些踢腿動(dòng)作對(duì)胎兒骨骼健康和關(guān)節(jié)發(fā)育至關(guān)重要。

Fetuses begin moving in the womb about as early as 7 weeks, when they slowly bend their necks, according to a review paper published in the journal Ultrasound in Obstetrics & Gynecology.

發(fā)表在《婦產(chǎn)科超聲》雜志上的一篇評(píng)論文章指出，胎兒最早在7周時(shí)就能在子宮中運(yùn)動(dòng)，那時(shí)他們會(huì)慢慢地彎曲脖子。

As the babies grow, they gradually add more movements to their repertoire, such as hiccupping, arm and leg movements, stretching, yawning, and thumb sucking.

隨著胎兒的生長(zhǎng)，他們的動(dòng)作會(huì)逐漸增多，例如打嗝、動(dòng)胳膊動(dòng)腿、伸展、打哈欠和吮吸拇指。

But the mom won't feel the bigger movements -- such as kicks and punches -- until 16 to 18 weeks into her pregnancy, when the baby is a bit stronger.

但孕婦只有到懷孕16周至18周時(shí)才能感受到幅度較大的動(dòng)作，例如踢腿和擊打，此時(shí)胎兒已經(jīng)更強(qiáng)壯了。

An entire field of research is dedicated to figuring out whether the baby is in control of its movement or if those movements are just a reflex, said Niamh Nowlan, a bioengineer at Imperial College London.

倫敦帝國(guó)理工學(xué)院生物工程學(xué)家尼婭姆·諾蘭稱，一個(gè)完整的研究正在致力于弄清楚是胎兒能控制這些動(dòng)作，還是說(shuō)這些動(dòng)作只是一種反射。

 

"Early movements are likely to be purely reflex," Nowlan told Live Science in an email, "but as the movements become more coordinated, it's likely the brain is in control of how much and when the baby moves."

諾蘭在發(fā)給《生活科學(xué)》的一封電子郵件中寫道：“早期的動(dòng)作很可能只是純粹的反射，但隨著動(dòng)作變得更加協(xié)調(diào)，很可能是大腦在控制胎兒的運(yùn)動(dòng)速度和時(shí)間。”

Scientists may not know for sure if the movements are voluntary or involuntary, but Nowlan said the research is clear that movement is important.

科學(xué)家們或許無(wú)法確定胎兒是主動(dòng)還是無(wú)意識(shí)做出這些動(dòng)作的，但諾蘭說(shuō)，研究明確了一點(diǎn)：運(yùn)動(dòng)很重要。

"The baby needs to move in the womb to be healthy after birth, particularly for their bones and joints," she said.

她說(shuō)：“胎兒需要在子宮里運(yùn)動(dòng)以保持健康，尤其是對(duì)他們的骨骼和關(guān)節(jié)而言。”

In a review she published in the journal European Cells and Materials, Nowlan described how alack of fetal movement can lead to a variety of congenital disorders, such as shortened joints and thin bones that are susceptible to fracture.

諾蘭在期刊《歐洲細(xì)胞和材料》上發(fā)表的一篇評(píng)論性文章描述了缺乏胎動(dòng)是如何導(dǎo)致各種先天疾病的，例如關(guān)節(jié)短和骨骼細(xì)，這些問(wèn)題容易引發(fā)骨折。

For pregnant women wondering if their baby is too kicky, or not kicky enough, Nowlan said there's no established amount of normal fetal movement during pregnancy. "Pregnant women are told to look out for significant changes in movements, which is quite vague advice, but it's the best that can be given at the moment," she said.

對(duì)于那些擔(dān)心寶寶胎動(dòng)太多或是太少的孕婦，諾蘭表示，在孕期胎兒運(yùn)動(dòng)并沒(méi)有固定的量。她說(shuō)：“孕婦被告知要注意胎動(dòng)的明顯變化，這是一個(gè)非常模糊的建議，但也是當(dāng)前能提供的最好的建議。”

That's because it's difficult for scientists to study fetal movements, because the only way to measure them is in the hospital and it can be done for only a short period at a time. It's unlikely that each woman will feel the same thing when her baby starts kicking.

這是因?yàn)榭茖W(xué)家很難研究胎兒的運(yùn)動(dòng)，要監(jiān)測(cè)它們的唯一方式就是在醫(yī)院里，而且只能在短時(shí)間內(nèi)完成。當(dāng)胎兒開(kāi)始踢腿時(shí)，每個(gè)準(zhǔn)媽媽的感覺(jué)可能不同。

"Different women experience the sensation quite differently, and sensations can vary between pregnancies," Nowlan said.

諾蘭說(shuō)道：“不同的女性對(duì)這種感覺(jué)的感受是完全不同的，而且同一個(gè)人每次懷孕期間的感覺(jué)也會(huì)有所不同。”

Feeling a baby moving and kicking in the womb might be a weird sensation, but it's simply a sign of healthy development.

感受胎兒在子宮中動(dòng)動(dòng)和踢腿或許是種怪怪的體驗(yàn)，但這其實(shí)不過(guò)是健康發(fā)育的跡象。