My husband and i both have a positive blood one of our children also has a positive the other o, how can that be? i don't know what our parents blood type .

A+ : A+ blood type means that one of the 2 blood type chromosomes (one from father and one from mother) carries a and the other carries either a or o: a+ blood = aa or ao. For one of your children to be a and the other 0, each of you must have one chromosome as a and the other as o (from your parents). Since each of you is ao, each child gets either an a or an o chromosome from one of you, so each child could be either aa, ao, or oo. Aa and ao = a blood type; oo = o blood type.

Genetics: The blood types are transmitted by common genetics. If both you and your husband are heterozygous for the positive gene, your child could end up as negative.