In the Netherlands, all pregnant women are offered blood tests early in pregnancy. One of the goals of this prenatal screening is to detect blood group antibodies. The Ministry of Health, Welfare and Sport has asked whether HPA-1a antibodies should be added to the screening.
If the pregnant woman is HPA-1a negative and the child HPA-1a positive, the pregnant woman can produce antibodies that break down the child’s platelets. When that happens, it is called FNAIT, a rare condition that can lead to brain haemorrhages. By testing for the presence of HPA-1a antibodies during pregnancy, the risk of FNAIT can be detected early and the pregnant woman can be treated preventively. It is expected that all FNAIT-related brain haemorrhages in unborn and newborn children can be prevented in this way. It is estimated that there are at least 4 per year.
The disadvantage is that not all pregnant women in whom HPA-1a antibodies are found are at risk of having a child with FNAIT. They are offered treatment based on the screening result, while they would not have had a child with FNAIT even without the screening and treatment. In that case, the weekly 3-hour treatment with an IV has been for nothing. Because the extent of this overtreatment is not clear at present, the Health Council cannot assess whether the benefit of the health gains to be achieved outweighs this disadvantage. This is why the Health Council advises not to offer screening for HPA-1a antibodies for the time being.
Because screening for HPA-1a antibodies could potentially prevent all cases of FNAIT, the Health Council believes it is important that there is more clarity about the expected extent of the overtreatment and about ways to reduce it responsibly.