Anti D: routine intervention debate

A medicine that offers a life line for a small minority has drifted into being used on a much wider population “just in case”.

If a medicine is good for a minority, then surely it’s even better to use it preventively on others? In this case, it appears that the logic doesn’t hold.

Our blood types are commonly understood – “O” “AB” etc. – and in addition we all have an Rh factor, which is the “positive” or “negative” aspect of our blood type. In the 1960s Anti-D was developed to help combat problems for Rh negative women with Rh positive babies, because an immune reaction to the baby’s blood can cause serious health problems in babies.

The people that this drug potentially benefits are:

  • Rh negative women with an Rh positive father of their child
  • Of these women, those who have experienced a trauma such as a car crash or interventions such as a C section during the birth

Originally, the drug was used in the 72 hours following a trauma or following birth interventions to stop an immune reaction in a future pregnancy. However, because studies found that women weren’t being offered the drug after trauma, in 1997 a consensus conference led to a recommendation to give the drug routinely rather than wait for a trauma to occur.

As with other birth culture issues we’ve covered, this is an area with large gaps in the research and a big lobbying pharmaceutical sector to deal with. National expert Sara Wickham has written about it in detail, well worth reading if you want to know more.

If you’re trying to make an informed choice on this intervention, one of the problems is that most of the literature available is produced or funded by the drug companies, rather than being independent. There is a US blog that offers some thoughts to help you (although from an activist not a medically qualified person).

The NHS page on this topic sadly doesn’t cover all the concerns raised by Sara Wickham. For example, if you are Rh negative but your baby’s father is too, then there’s no benefit from the drug, and it says that “it is likely small amounts of blood from your baby will pass into your blood during this time” which Sara points out is a contested point of view.

Rhesus disease can be serious for babies, and Anti-D may well be the best thing for those situations, but routine use of it on Rh negative women means passing the possible side effects onto mother and child without the benefits of preventing Rhesus disease to justify them. Sara points to some evidence suggesting it may even cause the disease in some babies by introducing the antibodies where they didn’t previously exist.