妊娠

胚胎与胎儿发育

随着受精卵发育成诞生时所见到的宝宝，受精卵要经历三个主要的发育时期：1.受精卵期（植入前期）；2.胚胎时期（妊娠早期）；3胎儿期（妊娠晚期）。因为受精卵期已经在“怀孕”一节里讨论过，现在转到讨论这个新生命有机体是怎样在子宫内发育的。

Pregnancy

Development of Embryo and Fetus

As the fertilized egg develops into the baby we see at birth, it goes through three main stages of growth: 1. the stage of the zygote (before implantation), 2. the stage of the embryo (early in the pregnancy), and 3. the stage of the fetus (later in the pregnancy). Since the first of these stages has already been discussed under "Conception", we now turn to a description of how the new organism grows inside the uterus.