I did pick up and turn the sac some because the cord seemed to be a bit twisted near its base. Hopefully that will help. The baby is very active and definitely does not like me messing around with it. If the sac doesn't change any further tonight I think I'll go ahead and tie it off and cut it away from the baby. If the baby isn't absorbing anything more from the sac I see no reason to make it wait for the thing to dry up and fall off.
Also, after looking in on this little guy/gal I realized I have eggs pipping. Pics are in the other thread.
Okay, the baby's yolk hadn't really changed at all so I cut it away. I used dental floss to tie off the cord near baby's belly and severed the connection with the sac. I actually had two tie off the cord twice because the little wiggle worm's first knotted piece of floss came off while I was pulling it tight. I also put him/her on the scale before moving to its own hatchling tub to see what it weighs.
Had this same thing happen except the baby dropped the sac on its own. I'm currently waiting on the first shed, but everything seems to be perfectly normal.
Same reason why you'd want to clamp an infant's cord before cutting it away from the placenta. There are blood vessels running through the cord to the sac and if you cut without clamping or tying it off, it could bleed out.