Whats rhesus negative blood?
Most people (80 per cent) have rhesus positive blood; the remainder have rhesus negative. Being rhesus positive means that the person has a substance called D-antigen on the surface of their red blood cells (this characteristic is inherited). When both partners have the same rhesus factor, there’s no problem, and neither is there a problem if the mother is rhesus positive and the father is rhesus negative. But if the mother is rhesus negative and the father is rhesus positive, and they have a baby who inherits rhesus positive status from the father, this can result in harm to the baby. During the pregnancy or birth, small amounts of the baby’s rhesus positive blood may cross over into the mothers bloodstream. The D-antigen on the blood cells can then trigger an immune response in the mother, causing her to produce antibodies against D-antigen. The mother is then said to be “sensitised” to rhesus factor. During a first pregnancy this may have no obvious effect, as sensitization don’t us
