How does an embryo get energy (glucose, etc.) - BEFORE it starts its own insulin production (around 13th week) (Feb/27/2011 )

The human embryo begins to produce its own insulin at around 13th week. How does glucose uptake happen into the embryo's cells prior to that?

Maternal insulin?

bob1 on Sun Feb 27 23:52:34 2011 said:

No, maternal insulin does not cross the placenta.

Glycogen is made by the placenta and stored in the trophoblast

pito on Mon Feb 28 09:14:49 2011 said:

But how is this glycogen delivered into the cells of the embryo, if there is no insulin available to facilitate the uptake?

cdog1350 on Tue Mar 1 04:16:03 2011 said:

I suppose the baby has still enough glucose to use even if there isnt insuline present. Not all uptake is regulated by insuline.
(wich has been proven in chicken embryos).

Anyway, check the papers I have added.