Fetal (3rd edit)

[Todd]

Hi, welcome to the site! Let me give you some comments below.

Lay in wait my breast-pumped heart--The language is evocative and on first pass it draws me in. A few things though, I don't get the sense of the past from this line, it could be me, but I think "Lie in wait" may be the right choice. While breast-pumped heart is interesting and conveys a sense of nurture, it doesn't make a lot of sense physcially.
as eggshells undulate, constant as mother--Gorgeous line. Love the soft image, the sense of rolling movement and the fragility of it all. You capture so much in those first three words. With the second phrase you have a nice sense of not only who the mother is to the speaker, but one of the best line breaks in the poem.
feeds my bones or moon-shucked nail beds.--I wonder why or instead of and. I love moon-shucked nail beds. Nail beds is a nice concrete choice. Moon-shucked gives me the sense of a few things (some of which may be off from your intent): the shape of the nail, the level of development skin with only the promise of nails, the passage of time with the addition of the moon. I'm okay with the slight ambiguity and I like the language choice.

Snipped in time my pose shifts--snipped umbilical cord, the pose shifting into birth.
naught but for the length of limb and the fold of my legs--I don't thank the more archaic naught serves you as well as nothing might. It's just a tad self-conscious. It's a style choice that I might disagree with, but it doesn't kill the poem.
beneath her thrumming atmosphere.--Love the imagery and sound of this line.

Hurried voices hush shuffles more eager than before--More eager than before seems a bit telling. I would look for another way to show the intensity around delivery rising.
until we submerge
my world in a blood-drawn bath----Beautiful line.
Jesus!--Now I realize later you're doing some pre-existent, higher consciousness stuff. And the idea of a baby relating to us with words is already a conceit. I just question whether the baby would know proper names, and use them in exclamation (Jesus or otherwise).  

Thrust to prismatic emprise--You would think there a blindness or a sudden shock before the awareness of color.
yet my consciousness stays
the shrunken severed memory
of mother's womb.--These last three lines acknowledge a loss in incarnating. 

It was interesting read, and I hope the comments help some.

Best,

Todd