Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare condition that affects the platelets in the fetus’ blood. Platelets are essential for blood clotting, and if the baby has FNAIT, it means the pregnant person’s immune system produces antibodies that attacks and destroys the fetus’ platelets. The fetal platelets are recognized as ‘foreign’ when they’re different from the mother’s platelets. This can lead to low platelet counts or thrombocytopenia, and in severe cases, it may cause bleeding problems in the fetus and newborn.
Fetal neonatal alloimmune thrombocytopenia (FNAIT) may not always present with noticeable symptoms in the mother or the baby. However, in severe cases, it can cause low platelet counts in the baby, which can lead to bleeding problems. Some potential symptoms of FNAIT in the baby include:
It's important to note that FNAIT can present differently in each case, and not all babies will show obvious symptoms. Additionally, some symptoms may only develop after birth. If you suspect FNAIT or have any concerns, discuss them with your healthcare provider, who can order appropriate tests and provide appropriate monitoring.
There is no routine prenatal screening for platelet incompatibility and risk of FNAIT. Generally, FNAIT is diagnosed after a first affected baby is born with signs such as petechiae, bruising, or bleeding, or low platelet count noted on routine blood testing.
The cause of FNAIT is incompatibility of the mother’s platelets with the fetal platelets leading to the mother producing antibodies against the fetus’s platelets. Women with a history of FNAIT in previous pregnancies are at increased risk.
Diagnostic tests for FNAIT include testing the mother’s blood for anti-platelet antibodies and genotyping (process of determining the genetic makeup) of the parents and fetus to see if they have different platelet antigens put them at risk for FNAIT.
FNAIT pregnancies used to be evaluated by fetal blood sampling (to check the fetal platelet count) and treated with intrauterine platelet transfusions. At times intravenous immunoglobulin (IVIG) is given weekly to the pregnant person. IVIG is not approved by health authorities for FNAIT.
Q. What causes FNAIT? A: FNAIT is caused by a mismatch between the platelet antigens of the fetus and the mother. When the mother’s immune system recognizes the fetus’ platelets as foreign, it produces antibodies that attack and destroy the fetal platelets.
Frequently Asked Questions (FAQs)
Q: How is FNAIT diagnosed? A: FNAIT can be diagnosed through a series of blood tests. These tests measure the genetic makeup of the mother, father, and/or the baby’s platelet type, and if the mother has platelet antibody.
Q: What are the symptoms of FNAIT in newborns?A: The most common symptom of FNAIT in newborns is a low platelet count, known as thrombocytopenia. This can lead to bruising, petechiae (small red or purple spots on the skin), or bleeding, such as nosebleeds or bleeding from the gums.
Q: How long does FNAIT last, and what is the long-term prognosis?A: The duration of FNAIT varies depending on the severity of the condition. In mild cases, platelet counts may return to normal within a few weeks. Severe cases may require more extended treatment, and there is a risk of long-term complications, such as bleeding or developmental delays.
Q: Is FNAIT a hereditary condition?A: FNAIT is not typically hereditary in the sense that it is directly passed down from generation to generation. The platelet antigen mismatch occurs between the fetus and mother during pregnancy, and subsequent pregnancies may also be affected.
Q: Can FNAIT affect future pregnancies?A: Yes, FNAIT can affect future pregnancies, particularly if the mother has had a previous baby with FNAIT. In subsequent pregnancies with a mismatched baby, there is a higher risk of developing FNAIT and its associated complications.
