The biggest problem you'll be facing is chick positioning inside of the egg prior to hatching, and deformities caused by two fetuses occupying one eggshell. May I remind everyone that an eggshelli in no way resembles the uterus of any mammal species known to science.
The yoke inside the shell is merely food for the developing chick while a human baby is nourished by an umbilical cord attached to a placenta . After 60 years with chickens I am unawares of any successful hatching of twin baby chicks from a double yoked egg. However I hope that 60 years with every type of chicken has taught me not to count my chicks before the double yoked egg hatches.
The yoke inside the shell is merely food for the developing chick while a human baby is nourished by an umbilical cord attached to a placenta . After 60 years with chickens I am unawares of any successful hatching of twin baby chicks from a double yoked egg. However I hope that 60 years with every type of chicken has taught me not to count my chicks before the double yoked egg hatches.
but it is nearly impossible to hatch these eggs anyway.
if you look up at post 186 you can see the big egg in the corner. I have candling pics but after day 14 it's hard to see anything 
