After 10 days she moved some of the
embryos back into natural wombs.
After 17 days she removed all embryos
and found that those left in vitro died
before reaching full term (21 days);
however, the embryos that had been
implanted back into mice seemed small
but otherwise normal(7). The endometrium
produced to help support embryo
growth and so was key to having the
mice continue to develop outside the
womb. Dr. Liu has also grown human
embryos to 10 days in artificial wombs
but no further because current federal
regulation in the United States prevents
growing human embryos beyond two
weeks in a lab(4).
Ideally, embryos could implant in the
artificial womb and at some point this
whole structure could be implanted
back into the woman. Since it would
have been grown using the woman’s
own cells there would be no fear of
organ rejection(8). Liu then tried implanting
mice artificial wombs carrying
embryos into adult mice; however, they
failed to survive, most likely because the