Blood of the person has both positive, and a negative Rhesus factor. Thus the person conducts a normal way of life and at all does not suspect about presence of a negative Rhesus factor – already till the pregnancy moment. Most strongly the Rhesus factor is displayed on mutual relations of mother and a fruit. Worst of all, if at the child positive, and at mum – a negative Rhesus factor. In this case a life of the child in danger.

To reduce to a minimum threat of a life of the child it is possible, if at the woman it is the first pregnancy, and to it was not neither abortions, nor abortions. However during the subsequent beremennostej complications are possible.