In patients who experience the rare immune blood disorder known as fetal and neonatal alloimmune thrombocytopenia (FNAIT) during their pregnancy, how to manage the condition is of key importance. In fact, a diagnosis of FNAIT and the necessary treatment can have a considerable impact on a mother’s physical, emotional, and social well-being.
What is FNAIT?
In FNAIT, the platelets of the fetus are attacked and then destroyed by the immune cells in the mother’s bloodstream. What subsequently occurs is that the mother recognizes the platelets from the baby as foreign, and she mounts an antibody response against these platelets. Such an immune response can happen when the mother’s blood becomes exposed to her baby’s blood—either while the fetus is in the womb or when the baby is being born.
Learn more about FNAIT treatment and care
How do platelets work?
Platelets, which are also known as thrombocytes, are a type of blood cell that helps the blood to clot. When there is an abnormally low level of platelets in the bloodstream, which is called thrombocytopenia, easy bleeding and rupture of blood vessels can occur. When a person is injured, platelets stick together and form a plug that seals the wound.
Platelets have natural proteins on their surface, which are known as human platelet antigens (HPAs). During pregnancy, half of these HPAs are inherited from the mother and the other half are inherited from father.
When FNAIT develops, maternal exposure to paternally inherited HPA on fetal platelets causes alloimmunization. This leads to formation of anti-HPA antibodies in the mother’s bloodstream. Fetal platelets are destroyed in the process and there is a risk for severe bleeding.
What are the signs and symptoms of FNAIT?
The signs and symptoms of FNAIT can vary among persons with the disorder. The severity of the symptoms that patients experience can vary as well. Symptoms of FNAIT can range from a low platelet count, which is known as thrombocytopenia, to signs of bleeding into the skin, including petechiae and purpura.
Petechiae are tiny spots of bleeding under the skin. Purpura occurs when small blood vessels leak blood under the surface of the skin, which leads to the appearance of red, purple, or brown blood spots on the skin.
The most severe but rare complication of FNAIT is intracranial hemorrhage (ICH). Also known as a brain bleed, ICH is a life-threatening medical emergency.
How is FNAIT managed during pregnancy?
No routine prenatal screening for FNAIT is currently available. If the disease is suspected, however, because of a prior medical history, parents can undergo screening.
During pregnancy, a diagnosis of FNAIT is typically managed by administering intravenous immunoglobulin (IVIG). IVIG is a noninvasive procedure in which a purified blood product containing antibodies manufactured from the pooled healthy blood plasma of thousands of donors is injected into the mother.
Occasionally, steroid tablets or steroid injections are recommended in addition to IVIG.
In severe cases of FNAIT, postnatal (after birth) platelet transfusions are administered to prevent bleeding.
