The fetal cells initially go undetected because the mother's immune system is suppressed during pregnancy.

胎儿细胞最初未被发现是因为母亲的免疫系统在怀孕期间受到抑制。

The mother can inherit fetal stem cells, undifferentiated cells that are able to develop into any specialized cell.

母亲可以继承胎儿干细胞，即能够发育成任何特化细胞的未分化细胞。

Keegan's embryo absorbed some fetal stem cells from her twin's embryo, which did not develop to term.

基根的胚胎从她双胞胎的胚胎中吸收了一些胎儿干细胞，但该胚胎并未发育至足月。

Well during fetal development, there are cells called neural crest cells, which are basically a group of fetal cells that migrate away and differentiate into a variety of different cell types.

在胎儿发育过程中，有一种细胞叫做神经嵴细胞，是一组由胎儿细胞迁移并分化成各种不同类型的细胞。

By day 8 the cells are sorting and arranging themselves - the green fetal cells have condensed together, and in red here are the cells that will form the interface between the baby and the placenta.

到第 8 天， 细胞开始自行分类和排列 - 绿色的胎儿细胞已经凝聚在一起，红色的是将形成婴儿和胎盘之间界面的细胞。