Your embryonic baby measures only 0.2–0.3mm in length, or about the size of a poppy seed.

By now the embryo has actually sunk beneath the surface of your uterus. The amniotic sac (the watertight bag of waters) and the amniotic cavity (the area within the womb that contains the amniotic sac, amniotic fluid, and developing child) have begun to form. The yolk sac, which eventually gives rise to the baby’s digestive tract, and a primitive version of the umbilical cord called the umbilical stalk appear. The amniotic sac, amniotic cavity, and yolk sac form over the next six days to create an environment in which your baby can grow and develop.

Your embryonic baby grows rapidly. The amniotic sac, amniotic cavity, primitive umbilical cord, and yolk sac continue to develop.

The divided cell mass now looks like two hollow balls opposing each other suspended from a thick, short umbilical stalk and encased by a fluid-filled bubble.

The Miracle of Life

Poppy seed - week 4.PNG