If you and husband are both rh- then you may prefer a donor who is also rh- for health reasons (not sure how important this is these days). Otherwise, if you are 100% no tell, look at this chart for your blood types and find a donor who will produce the same possibilities in children. For example if you are A+ and husband is B+, you can in theory (not knowing if you are AO or AA and if he is BO or BB) produce any blood type child and so any donor blood type is fine. But if you are A+, husband is O+, and potential donor is B+, there's a good chance you'll have a child who could not genetically belong to you both. Does this matter to you? Being single, blood type was pretty unimportant to me but if I wanted to "retrofit" my O+ and B+ kids to a potential partner, as an A+, he'd have to be B+ or B-. If it doesn't matter to you and you are RH+, the sky is the limit.