I to have O negative blood, and have struggled with giving birth to a live baby, my body had a habit of terminating my babies but it never miscarried, having to have anti D, & I have learnt I will not be able to have an organ transplant, bot sure if thats true, but our blood banks are always after my blood group as its given to anyone else, as children we have no concept of what things really mean, but twins have a bond like no other even fraternal twins