Mana is the life energy of elves that allows it to function. These elves are similiar in design to human beings. When an elf becomes pregnant, the developing fetus feeds off of its mother's mana, abosrbing it into itself and allowing it to grow. This is minimal during the first few months, with more mana being necessary at the later stages. During this time, the elf is unable to use magic. This prohibition ends after the child is born, with mana storage rising to normal levels.
Occasionally, a condition known as mana leakage occurs during this process. This happens when mana being fed to the fetus is not absorbed completely, with some of it leaking back into the mother. This is dangerous to the mother, and child, and can lead to the death of both parties. If not caught in time, this can lead to a number of effects, such as:
Mana poisoning of the mother
Child born with abnormalities, such as disfigurements.
Hot flashes, in which mana fatally overheats the body.
Why would a elf's own mana be dangerous to her?