Mink Hollow Farm

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Why can't we do Caesarean Sections on eggs?

“Front View”	Bird embryos are not supported by placentas as mammals are. Instead, there is a network of blood vessels that lines the shell and ends up in an umbilical cord that is attached to the duckling at its 'belly button'. When the duckling is ready to hatch, it breaks into the air cell and begins to breathe. This triggers the network of supporting blood vessels to begin to shut down. All the blood from these vessels must drain into the duckling before it is ready to hatch.	“Rear View”
	The duckling's struggles and movement help this process and by the time it is ready to hatch, there is no more blood in the vessels that line the shell. If the shell is broken before this network of blood vessels has stopped functioning, and one or more of these vessels is damaged, there will be bleeding. Baby birds don't have a lot of spare blood, and so this can be dangerous.
When a mammal is born, the umbilical cord is usually crushed before the baby is born, so it does not bleed. During a caesarean section, the cord is clamped before being cut for the same reason. It is simply not possible to clamp the cord of a baby bird before breaking the shell, so opening the egg while that network of blood vessels is still functioning will cause many to be torn, which would be the same as tearing open (or removing) the placenta while the baby is still using it. The baby will bleed to death.
Timing is everything. If these blood vessels have ceased functioning and contain no more blood, it is safe to remove the baby bird, but not before.