True Joanne, it is very fast, but one of my points about this is that, when a baby is found to have a Weak or Partial D (such as Partial DVI), it would be good practice to test the mother for Weak or Partial D expression, if this has not already been done, because she may be the source of the mutant gene leading to the baby's Weak or Partial D type. If she is the source, then it is a moot point, to say the least, as to whether she should or should not be exposed to a human-derived blood product that may, for all we know, be harbouring novel virus that may be transfusion-transmitted. AT the very least, she should have the risk, albeit very low, explained to her before she is given the anti-D immunoglobulin.