Part of Speech- Noun
Definition-Ā a medical condition in which the ability of the blood to clot is severely reduced, causing the sufferer to bleed severely from even a slight injury. The condition is typically caused by a hereditary lack of a coagulation factor, most often factor VIII.
Source- Dictionary.com
“The Child Bearer” by Anne Sexton
In the poem, the speaker is using the word to describe being passed on like a genetic disease.