Until then, doctors had assumed that an embryo missing all Rh blood cell antigens would not survive, let alone grow into a normal, thriving adult.

在此之前，医生们一直认为缺少所有Rh血细胞抗原的胚胎无法存活，更不用说成长为一个正常、茁壮的成年人了。

But, as the name implies, the Rhnull blood type is completely missing these Rh blood group antigens, which makes it the rarest blood type in the world.

但是，正如该血型名字所暗示的那样，Rhnull血型便没有这些Rh血型抗原，这使它成为世界上最罕见的血型。