懷孕時,肚子裏的寶寶幾乎所有的時間都在睡覺大綱

Sleep is the single most effective thing you can do to reset the health of your brain and body. This is true for adults, teenagers and children alike.

睡覺是重置大腦和身體健康的最有效方法。對於成年人來說如此，對於青少年和兒童來說也是如此。

Yet, we do not start sleeping when we are born. We actually start sleeping many months before that. Often, through speech or song, expecting parents will thrill at their ability to elicit small kicks and movements from their in-utero child.

但我們並不是出生的時候纔開始睡覺。事實上，早在出生前幾個月我們就開始睡覺了。通常，父母希望通過說話或音樂激發子宮內的寶寶踢一踢或動一動。

Though you should never tell them this, the baby is most likely fast asleep. Prior to birth, a human infant will spend almost all of its time in a sleep-like state, much of which resembles a stage called rapid eye movement sleep, or REM sleep. The sleeping fetus is therefore unaware of its parents' performative machinations.

雖然你永遠都不該告訴他們，但子宮內的寶寶很有可能睡的很熟。出生之前，嬰兒幾乎所有時刻都處於睡眠狀態，其中大部分過程與淺睡眠階段相似。因此，正在睡眠狀態中的寶寶根本就不知道父母的表演意圖。

Any co-occurring arm flicks and leg bops that the mother feels from her baby are most likely to be the consequence of random bursts of brain activity that typify REM sleep. Adults do not-or at least should not-throw out similar nighttime kicks and movements, since they are held back by the body-paralyzing mechanism of REM sleep.

母親感受到的寶寶的任何動作（胳膊動了或腿動了）都很有可能是淺睡眠階段大腦活動隨機爆發的結果。成年人不會--至少說不應該--在夜裏有類似的踢動或動作，因爲這些動作被淺睡眠時的身體癱瘓機制制止了。

But in utero, the immature fetus's brain has yet to construct the REM-sleep muscle-inhibiting system adults have in place. Other deep centres of the fetus brain have, however, already been glued in place, including those that generate sleep.

但在子宮內，嬰兒大腦還未成熟，不能構築成年人已有的淺睡眠階段肌肉抑制體系。然而，嬰兒大腦擁有的其它深層中心已經就位，包括觸發睡眠的中心。

As a result of this mismatch, the fetus brain still generates formidable movement commands during REM sleep, except there is no paralysis to hold them back. Without restraint, those activity signals are freely translated into frenetic body movements, felt by the mother as acrobatic kicks and featherweight punches.

由於這種搭配不當，嬰兒的大腦仍會在淺睡眠階段發佈強大的運動指令，但是卻沒有癱瘓系統抑制這些動作。沒有了限制，這些活動信號可以自由的轉化爲狂熱的身體運動，而母親則將其視作孩子雜技般的踢動和"綿綿拳"。

At this stage of in-utero development, most of the time is spent in sleep, split between REM sleep and deep sleep, also called non-REM sleep.

在子宮內發展的階段，嬰兒大多數時間都在睡覺，分爲淺睡眠和深度睡眠。

It is only when the fetus enters the final trimester that the glimmers of real wakefulness emerge. Far less than you would probably imagine, though-just two to three hours of each day are spent awake in the womb.

只有在最後三個月，清醒纔會微露光芒。但比你想象的少多了--每天在子宮內只會醒2至3個小時。