Learn The BasicsIf a baby is at high risk of fetal and neonatal alloimmune thrombocytopeniaFetal and neonatal alloimmune thrombocytopenia A rare condition in which a mother’s immune system attacks fetal platelets, leading to dangerously low platelet levels before and/or after birth. (FNAITFetal and neonatal alloimmune thrombocytopenia A rare condition in which a mother’s immune system attacks fetal platelets, leading to dangerously low platelet levels before and/or after birth.), the mother and the baby should be offered treatment and care to reduce the risk of the baby developing complications such as intracranial hemorrhageBrain bleed Bleeding inside the fetal brain, also known as an intracranial hemorrhage. In FNAIT, it's often caused by severe thrombocytopenia and can lead to long-term disability or death. (also known as ICH) and long-term complications associated with it.
These include fetal treatment and care before the baby is born and neonatal treatment and care right after birth.
Prenatal treatment and care
Prenatal treatment and care involves treating a pregnant woman or a fetus. The mother could be treated with intravenous immunoglobulinIntravenous immunoglobulin A treatment given to pregnant women with a history of FNAIT or known alloantibodies. IVIG reduces the immune reaction against fetal platelets. (IVIGIntravenous immunoglobulin A treatment given to pregnant women with a history of FNAIT or known alloantibodies. IVIG reduces the immune reaction against fetal platelets.) or corticosteroids while the fetus may be given intrauterine platelet transfusions.
Maternal IVIG
Because FNAIT is the result of a pregnant woman’s immune system mistakenly attacking her baby, dampening her immune system while she is pregnant may be helpful. This is the goal of IVIG treatment.
This is currently the “gold standard” for pregnancies at risk of FNAIT. Women who have had a previous baby with FNAIT and ICH may be given IVIG as early as the 12th week of their pregnancy.
Maternal corticosteroids
Another way to dampen the immune system of the mother is corticosteroids, which are anti-inflammatory drugs that reduce the production of chemicals causing inflammation. These are sometimes given to pregnant women at risk of FNAIT together with IVIG.
Intrauterine platelet transfusionPlatelet transfusion A treatment for newborns with very low platelet counts that ideally uses HPA-compatible or washed maternal platelets.
In FNAIT, the body of a pregnant woman makes antibodies against a protein called Human Platelet AntigenHuman platelet antigen Proteins found on the surface of platelets. Incompatibility between maternal and fetal human platelet antigens can trigger FNAIT. (HPAHuman platelet antigen Proteins found on the surface of platelets. Incompatibility between maternal and fetal human platelet antigens can trigger FNAIT.) that is found on the surface of her baby’s platelets. Platelets are small fragments found in the blood that are responsible for blood clotting. This immune attack results in the baby’s platelets being destroyed causing low platelet counts and an increased risk of heavy bleeding.
One way to increase the levels of platelets in the fetus is to give them platelets from a donor. However, this is a very high-risk procedure and is not often preferred, as the baby is already at high risk of bleeding.
Another reason this approach is rarely used is because the half-life of platelets is very short, meaning the transfusion must be repeated weekly.
Postnatal treatment and care
A baby at risk of FNAIT who is born with signs and symptoms of FNAIT such as bruising, petechia or purpura may need to be admitted to the neonatal intensive care unit. There, the baby may be treated with a platelet transfusion, IVIG and or corticosteroids.
They may also undergo a cranial ultrasound to check for the presence of ICH.
Platelet transfusion
In babies with low platelet counts, a platelet transfusion can be life-saving.
If possible, HPA-matched platelets should be used, but if these are not available, HPA-unmatched platelets may also be used.
IVIG
A newborn with FNAIT may also receive IVIG therapy in an attempt to increase their platelet countPlatelet count A measure of how many platelets are in the blood. FNAIT is characterized by severely reduced counts in a fetus or newborn.. However, it is not clear how effective this treatment approach is.
Corticosteroids
Similarly, corticosteroids may be used together with IVIG in the treatment of a newborn baby with FNAIT, but again, the benefits of such an approach are not clear.
