Source: http://unbornwordoftheday.com/2010/12/05/what-does-my-little-savior-look-like-first-trimester/

On this Day of the Unborn Child – keeping in mind the pregnant Virgin Mary and her growing unborn baby – this is a good time to ask, “What does our little Savior look like?”

The Zygote Christ Child is a mere one cell and you can’t even see Him. This cornerstone cell of the Christ Child’s Body is a male human living cell with 46 chromosomes. Jesus at this  one cell stage is literally bursting with Grace! This is “the grace of union”, when the Son of God assumed a human nature from His very conception, which St. Thomas Aquinas taught was the source of every other grace.  He is One Cell and one with us.

The Blastocyst Christ Child at about one week development now consists of more than 100 cells; a one hundredfold blessing for humanity. He is implanted into the lining of Mary’s womb and is clearly focused on His Incarnation Mission.

The Embryonic Christ Child is between 1/12 to 1/6 of an inch in length (around 4 weeks gestation). He is “the least among us” but has the most to give! His primitive Sacred Heart is beating for love, a tempo that this world has never heard before, with a meaning that will take a life time to comprehend. (Memo to Mary: Your little baby has taken charge of this redemptive pregnancy already, sending chemical-hormonal messages from His body to yours – thank you Mary for passing on essential nutrients to your Embryonic Christ Child, you are building up His tiny body and preparing Him for His Redemptive Mission.)

The Fetus Christ Child (around 8 weeks gestation) is 1 ¼ to 1 2/3 inches in length and weighs about 1/3 ounce. He is not heavy, He is our brother, in solidarity with all unborn children, embracing our humanity in His body and Soul. In proportion to the rest of His rapidly growing body, Christ’s head and heart are very big; He knows us and loves us. His Sacred Heart beats at about 140 beats per minute.

As His First Trimester ends, Unborn Jesus shows extraordinary signs of typical growth for an unborn baby. All vital organs are fully formed, His hair is growing, you can count the fingers on His hand and His finger nails are growing too! See each ear taking on its final shape and the iris forming in His eye. “Incline thy ear, O Lord, and hear; open thy eyes, O Lord, and see….”(Isaiah 37:17) In the buoyant liquid environment in which He grows, Unborn Jesus is showing not just a ‘walking reflex’  but vigorously stretches His limbs and can even be seen leaping.

“Behold, he comes, leaping upon the mountains, bounding over the hills.
My beloved is like a gazelle, or a young stag.
Behold, there he stands behind our wall, 
gazing in at the windows, looking through the lattice.”   Song of Songs 2:8-9