Understanding the risk of blindness in children with FNAIT

Photo shows a doctor looking at MRI scans of a baby's brain/Getty Images
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Learn more about intracranial hemorrhages, a rare but serious complication of FNAIT that could lead to blindness.

Intracranial hemorrhage (ICH) is the most dangerous complication of fetal and neonatal alloimmune thrombocytopenia (FNAIT). If severe thrombocytopenia develops in the fetus or newborn, it can lead to ICH. Long-term consequences of ICH include cerebral palsy, brain damage, epilepsy, hearing loss, development delays, blindness and even death.

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare but serious condition that affects 0.1% of pregnancies in which a pregnant mother’s immune system produces antibodies against the platelets of her fetus. This occurs when a fetus inherits platelet antigens from the father that are not compatible with the mother, typically involving a protein called human platelet antigen (HPA). The mother’s immune system recognizes the fetal platelets as foreign, attacking and destroying them, leading to low platelet levels (thrombocytopenia) in the fetus or newborn.

What is an intracranial hemorrhage?

When the mother’s immune system attacks the baby’s blood platelets, the result is the onset of thrombocytopenia. When the blood platelet levels are very low, blood can no longer clot, leading to uncontrollable bleeding or hemorrhage.

An intracranial hemorrhage is bleeding on the brain, and it can develop in severe cases of FNAIT, during pregnancy or post-delivery. It occurs in one in 12,500-25,000 births, with a recurrence rate of 79% in subsequent pregnancies. ICH most commonly occurs during pregnancy, with up to 50% of hemorrhages before 32 weeks, and there is a high risk for miscarriage when ICH develops in utero.

Learn more about FNAIT signs and symptoms

How can ICH lead to blindness?

FNAIT-related blindness is a rare complication of ICH, but the risk remains. Bleeding on the brain can cause bleeding near the optic nerve, visual cortex or retina, leading to partial or total blindness. If ICH is diagnosed in a baby affected by FNAIT, regular follow up neurologist assessments and eye tests will be scheduled.

There is no standard prenatal screening program for FNAIT and while it can develop during pregnancy, cases are often only diagnosed following delivery. The best way to prevent blindness in infants with FNAIT is by not allowing ICH to develop. Early detection and immediate treatment of FNAIT symptoms are key to avoiding severe thrombocytopenia, which can lead to ICH.

Fetal FNAIT is treated with the weekly maternal administration of intravenous immunoglobulin (IVIG) with or without steroids, to suppress the mother’s immune response against fetal platelets.

In newborns, suspected FNAIT based on symptoms of bruising, bleeding, skin discoloration with red or purple spots, low platelet counts and potentially, ICH requires urgent blood platelet transfusions.

FNAIT is possible during first pregnancies and a confirmed diagnosis is important to ensure proactive, preventative measures are taken in subsequent pregnancies to prevent or delay the onset of FNAIT. IVIG therapy is administered in pregnancies at risk of FNAIT even before symptoms are detected.

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