concern2:My kids were born in KK - no indication of blood group on the Health booklet.According to some research I've done over the web, if both parents have blood group 0+/-, the children will be 0+/-.If either one of the parent is A or B, that will 'supersede' the 0 group, and the children will be A or B, depending on the blood group of that parent.I know of a family with Father who is A and mother who is AB. None of the kids are 0 group, and all the 5 kids are: A, AB, B, A and AB!!Remembered studying these in Bio class in sec sch... together with dominant & recessive gene... hehe.My boy's delivered @ Raffles... blood group indicated in Health Booklet.