Name: The surprising effects of pregnancy
Uploaded: 2020-12-07T18:12:09.000Z
Duration: 5 min 46 s

The heart's pounding rhythm speeds up.  Blood roars through arteries and veins.

Over the course of a pregnancy,  every organ in the body changes.

these changes begin  as soon as pregnancy begins.

在妊娠過程中， 體內的每個器官都發生變化。

Just days after fertilization, the embryo  implants in the lining of the uterus.

Because its DNA doesn't exactly match  the mother's,

the immune system should theoretically  recognize it as an invader,

在受精後的幾天內， 胚胎就會被植入子宮內膜。

attack, and destroy it, like it would  bacteria or other harmful microbes.

因為它的 DNA 與 母親的 DNA 不完全匹配，

That's the challenge:  the mother's immune system

所以，理論上講，免疫系統 會將它視為一個入侵者，

needs to protect both her and the fetus,  but can't act as it usually does.

從而對其實施攻擊和摧毀，就如同 對待細菌和其他的有害微生物一樣。

What happens is not as simple  as decreasing the immune response.

這是一個挑戰：母親的免疫系統

Instead, it's a complex interaction  we're just beginning to understand,

需要同時保護自身和胎兒， 但又不能像通常那樣運作。

involving many different types  of immune cells—

事情並不像降低 免疫反應那麼簡單。

some of which seem to protect the fetus  from attack by other immune cells.

相反，這是一個複雜的相互作用， 我們對此也才剛剛有所了解。

The body also creates an antibacterial  plug made of mucus on the cervix,

它涉及許多不同類型的免疫細胞——

which keeps germs away  and stays sealed until labor.

其中一些細胞似乎在保護胎兒 免受其他免疫細胞的攻擊。

人體還在子宮頸上製造了 一個由粘液構成的抗菌栓，

the uterus expands upward and outward  with the growing fetus.

它可以防止細菌入侵 並保持密封直至分娩。

To make room, hormones  called progesterone and relaxin

子宮會隨著胎兒的生長 而向上和向外膨脹。

The muscles that propel food and waste  through the digestive tract also loosen,

為了騰出空間，兩種被稱為 孕酮和鬆弛素的激素

causing constipation as passage  through the tract slows down.

那些在消化道內推動食物 和排泄物的肌肉也會變得鬆弛。

Loosened muscles  at the top of the stomach

might allow acid to escape  into the esophagus and throat,

從而造成便秘，因為其通過 消化道的速度放慢了。

These changes can worsen morning sickness,

可能會使胃酸逸入食道和咽喉，

which is caused in part by hormone HCG—  and can also happen at other times of day.

As the uterus grows,  it pushes on the diaphragm,

the muscle that expands and contracts  the chest with each breath.

它部分是由 HCG 激素引起的—— 也可能發生在一天中的其他時間。

隨著生長，子宮會擠壓橫膈膜；

To compensate, the hormone progesterone  acts as a respiratory stimulant,

橫膈膜是每次呼吸時 控制胸腔擴張和收縮的肌肉。

making the pregnant woman breathe  faster so both she and the baby

這就限制了橫隔膜的運動範圍。

can both get enough oxygen  with less lung capacity.

作為彌補，黃體酮激素發揮了 呼吸興奮劑的作用，

This all may leave the pregnant woman  feeling short of breath.

它使孕婦呼吸加快，以便讓她和胎兒

Meanwhile, the kidneys  make more erythropoietin,

在肺活量減小的情況下 都可以得到足夠的氧氣。

a hormone that increases  red blood cell production.

這都可能使孕婦感到喘不過氣。

The kidneys also keep extra water and salt rather than filtering it out into urine

同時，腎臟製造出 更多的紅血球生成素，

A pregnant woman's blood volume  increases by 50% or more.

腎臟還把額外的水和鹽分儲存了 起來，而不是將其過濾到尿液中

because it only has 25%  more red blood cells.

孕婦的血液容量會增加 50％ 以上。

Usually, the body makes blood cells  using iron from our food.

But during pregnancy, the fetus  is also building its own blood supply

因為它的紅細胞只增多了 25％。

通常，人體利用食物中的 鐵元素製造血細胞。

leaving less iron and other nutrients  for the mother.

但是在懷孕期間，胎兒也在 建立自己的血液供應，

The heart has to work extra hard  to pump all this blood

從母親的食物中吸收營養成分——

從而減少了母親體內的 鐵和其他營養成分。

but we don't fully understand how blood  pressure changes in a healthy pregnancy—

才能把血液泵送到全身和胎盤。

because some of the most serious  complications

但我們還不完全了解 血壓在健康妊娠內如何變化——

are related to the heart  and blood pressure.

The expanding uterus may press on veins—

causing fluid buildup  in the legs and feet.

If it presses on a large vein  called the inferior vena cava,

it might interfere with blood  returning to the heart,

causing a dizzying drop in blood pressure  after standing for too long.

如果壓迫在被稱為 下腔靜脈的大靜脈上，

Some of these changes start  to reverse even before birth.

它可能會干擾到血液回流到心臟，

Shortly before delivery,  the fetus drops down,

站立過久後，會造成血壓下降， 令人感到眩暈。

其中一些變化甚至 在嬰兒出生前就開始發生逆轉。

and allowing the pregnant woman  to take deeper breaths.

much of the extra fluid in the body  is lost when the water breaks.

The uterus shrinks back down  in the weeks after birth.

Like the rest of the body,  pregnancy affects the brain—

體內的大量積水 會因羊水破裂而流失。

but its effects here are some  of the least understood.

子宮會在分娩後的幾週內收縮。

Recent studies show differences  in brain scans

像身體的其他部分一樣， 妊娠會影響到大腦——

但是我們對此處的影響卻知之甚少。

and suggest that these changes  are adaptive.

That means they could help  with parenting skills,

在妊娠後及早期育兒階段 存在著大腦掃描上的差異，

such as an increased ability to read  facial cues since babies can't talk.

The lack of information about pregnancy's  effects on the brain

highlights a general truth: historically,  almost all the research around pregnancy

比如，由於嬰兒不會說話，對面部 表情的解讀能力因此而得到提高。

has focused on the fetus,  rather than pregnant women.

缺乏有關妊娠對大腦影響的信息

突顯出一個普遍的事實： 幾乎所有歷來關於妊娠的研究

both within the range  of healthy pregnancies

and due to complicating health conditions— new research will help us understand why,

對妊娠的體驗存在著很大差異。

and develop effective treatments  where necessary.

In the meantime,  every pregnancy is different,

and it's important to consult a doctor  with any specific questions.

新的研究將幫助我們了解其原因

並開發出必要和有效的治療方法。

as more research is devoted  to the astounding biology of pregnancy.