The management of women with red cell antibodies during pregnancy is one of those ones I think it is worth us knowing a bit about, as it does come up, but mostly these women will be managed by obs.
In about 1.2% of pregnancies, women will have red cell antibodies. In about 0.4% of pregnancies this will cause a clinically significant problem. They are generally checked at booking and at 28 weeks and occasionally we are the ones looking at the result and making a decision about what to do.
What is the significance of this?
The presence of red cell antibodies means that allo-immunisation has occurred. This can be due to a previous pregnancy, transfusion or transplant. These antibodies can cause Haemolytic Disease of the Fetus and Newborn (HDFN). Maternal IgG antibodies to the baby’s antigens cross the placenta. This can cause haemolysis in the baby, both in utero and neonatally, which can lead to a need for intrauterine or neonatal transfusion, jaundice or perinatal loss.
There can also be significance for the mother in that it may be more difficult to get appropriately matched blood for transfusions.
Some antibodies are very significant and others have less significant effects. They are listed in the appendix to the guideline, so look them up if the result is one you're not sure about and obviously seek advice. The most important ones are:
- Anti-K (anti-Kell)
Other significant ones are: Anti-E, Anti-Fya, Anti-Jka, Anti-C and Anti-Ce
Implications for us
Women with known red cell antibodies may need referral for pre-pregnancy counselling.
Women with known red cell antibodies or previous HDFN who become pregnant, need obs referral.
It is unlikely that we are going to know the significance of what antibodies are found, so we are going to need to at least discuss it with obs, or refer in.
Neonates are at high risk and are likely to be kept in hospital longer for monitoring.
The mother will need to feed the baby regularly to avoid dehydration, which increases risk