Of all placental mammals, handicaps are the tiniest in comparison to their mother.

在所有胎盘哺乳动物中，与母亲相比，残疾是最小的。

This is our best guess at what the first placental mammal looked like.

这是对第一种胎哺乳动物外貌的最好猜想了。

Tissue refers to placental fragments retained in the uterine cavity.

Tissue指的是胎盘组织部分残留在子宫腔中。

It's then carefully removed to ensure that there are no placental remnants left in the uterus.

然后慢慢移除，确保胎盘遗留物不会留在宫腔。

Therefore, you need to get your oxygen from the mother's placental blood flow and all that stuff.

因此，你需要从母亲的胎盘血流和所有的东西中获。

Apparently, her fall caused a placental abruption, where the placenta separates from the uterus. -Oh, my god.

很明显，她的跌倒致胎盘破碎，胎盘和子宫已经分离了。-天哪。

But you have an early placental abruption.

但你过早出现了胎盘早期剥离。

But in 1960, many experts believed that the placental barrier shielded a fetus from harm.

但在 1960 年，许多专家认为胎盘屏障可以保护胎儿免受伤害。

That's because, typically, the larger a placental land mammal is, the longer its pregnancies are.

这是因为，通常情况下，胎盘陆地哺乳动物越大，其怀孕时间就越长。

The three modern mammal groups -- the placentals, marsupials and monotremes -- all made it.

三个现代哺乳动物群——胎盘 动物、有袋动物和单孔动物——都成功了。

Risk factors for placental abruption include acute events like blunt trauma from a car accident, fall, or domestic violence.

胎盘早剥发的危险因素包括突发事件如车祸创伤、坠落伤或者家庭暴力带来的伤害。

There's a membrane called the placental barrier that's supposed to stop really terrible things like mercury from getting through to the fetus.

有一种叫做胎盘屏障的膜可以阻止非常可怕的物质，比如汞进入胎儿。

Paraceratherium was a placental mammal, like us, meaning that it gestated its young inside its body.

Paraceratherium 是一种胎盘哺乳动物，就像我们一样，这意味着它在体内孕育了幼崽。

Given that placental abruption leads to a serious blood loss from large vessels, it's considered an emergency.

如果胎盘早剥致大血管严重出血，则被认为是紧急情况。

These extreme blood pressures can lead to a hemorrhagic stroke or placental abruption, in which the placenta detaches prematurely from the uterine wall.

这种严重的高血压可能致出血性脑卒中或者胎盘早剥，即胎盘从子宫内壁过早脱落。

Because all of the problems of preeclampsia and eclampsia stem from placental dysfunction, the ultimate treatment is delivery of the fetus and placenta.

由于子痫前期和子痫的所有病理变化都起源于胎盘功能障碍，所以治疗的根本方法是使胎儿和胎盘娩出体外。

But finally, around 160 million years ago in the Late Jurassic Period, the ancestors of placental mammals and marsupials appeared.

但最终， 大约在 1.6 亿年前的侏罗纪晚期，胎盘哺乳动物和有袋动物的祖先出现了。

With uterine atony, though, the uterus fails to contract after birth, and those placental arteries don't clamp down, leading to excessive bleeding.

不过，对于子宫收缩乏力的患者，她们的子宫肌层在产后不能继续收缩；没有压力作用于胎盘动脉，致失血过多。

The researchers suggested that the ancestors of placental mammals that lived with the dinosaurs were small, insectivorous, and nocturnal.

研究人员认为，与恐龙一起活的胎盘哺乳动物的祖先体型小、食虫且夜间活动。

For example, the African elephant, the largest placental land mammal today by mass, has a gestation period of up to 2 years.

例如， 非洲象是当今质量最大的胎盘陆地哺乳动物，妊娠期长达 2 年。