Haemolytic Disease of the Newborn (HDN)

Giving Birth

Let’s say that an RhD-Negative mother gives birth to a normal, healthy but RhD-Positive, baby. During the birth, as often happens, a small amount of baby’s blood crosses over into the mother’s blood circulation. The mother’s immune system gradually responds and destroys the RhD-Positive blood.

From now on the mother’s blood will always ‘remember’ RhD-Positive blood cells.

Now, let’s suppose the mother becomes pregnant with a second child who is also RhD-Positive. There is a real risk that RhD Factor antibodies from the mother can cross the placenta and enter the baby’s blood stream.

These antibodies, which were produced in the first place to protect the mother, now have the opposite effect on the baby. They can damage the baby’s red blood cells. If this happens, the baby can suffer a number of life-threatening conditions, collectively known as ‘Haemolytic Disease of the Newborn’ or ‘HDN’ for short.

Please contact your GP or Midwife, for further information about the RhD Factor and what it means to you.