Regarding blood incompatibility. This!

It a false notion that your relative is harboring. O -ve is a blood group of the lady and if a lady with ANY negative blood group marries a man with a positive blood group, there are chances that the baby can be -ve (50%) and +ve (50%), so if the baby is say positive, its blood group will be known ONLY AFTER birth. In such situation Imagine a negative blood group lady having a positive blood group baby in her tummy for 9 months. Normally the mothers and baby's blood doesnt mix, but in some circumstances it can. When the positive blood cells mix in the mothers body, the mothers body sets upa defence and destroys these blood cells. But it retains the memory of such an intrusion and if the mother gets another leak of baby's blood cell, the response of destroying the baby is excessive and hence there are chances that the baby may not survive, or get its; blood destroyed and also cause a heart failure in the intra uterine life. Though i have said the above things, I must say the possibility of this happening are RARE, as in most pregnancies happening to negative blood group mothers there is NO mixing of the baby's blood and in such Negative blood group mother we check up the blood in her pregnancy and give her a injection of antibodies which can destroy such cells if leaked. This is also done after delivery withing 72 hours. In my 25 years of practice i havent seen a single such case where the negative blood group lady has problems. Yes, O -ve blood group is not very common, so the patient has trouble finding blood for surgery etc but then every surgery doesnt require blood nowadays with modern technology where we see to it that blood loss is minimised and blood transfusions avoided

Marry a person based on your liking of her, her education, family background, etc criteria. Blood group is NOT a criteria to reject anyone. Again If any blood group is absolutely incompatible with yours it is AB-ve, and not o -ve, so be wise and chooce wisely