When pregnant woman is at risk of fetal and neonatal alloimmune thrombocytopenia (FNAIT), the use of intravenous immunoglobulin (IVIG) is the first-line, or most commonly used, treatment to delay the onset of severe FNAIT symptoms and complications.
Corticosteroids can also be given as part of this treatment, but the evidence for their use is less strong, and fetal and maternal side effects can be significant.
What is FNAIT?
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 are corticosteroids?
Corticosteroids, including prednisone, are steroids used to treat pain and inflammation in diseases where the immune system mistakenly attacks its own systems. In pregnancies affected by FNAIT, they are used in combination with IVIG, where they suppress the pregnant mother’s immune system to slow the production of the maternal antibodies that attack the fetus’s blood platelets.
Learn more about FNAIT treatment and care
This slows the destruction of the fetal blood platelets and delays the onset of severe fetal thrombocytopenia and potentially life-threatening complications such as intracranial hemorrhage (ICH).
Use of corticosteroids in FNAIT pregnancies
IVIG can be administered with or without corticosteroids. The addition of corticosteroids to IVIG is made to support its efficiency and also to reduce the onset of headaches in pregnant women. However, there is little evidence to show that there is an increase in platelet count when prednisone is added to IVIG.
The administration of corticosteroids is also recommended in pregnancies where the baby is at risk of being born prematurely, between 24 and 35 weeks gestation. Corticosteroids are given to reduce complications associated with premature delivery, such as breathing problems, bleeding on the brain and developmental delays.
When used with IVIG, the corticosteroid dexamethasone should not be used due to significant side effects. Corticosteroids can be administered in several ways, including as an injection in your upper thigh or arm or as a pill taken orally.
Side effects of corticosteroids use
A variety of side effects are associated with the use of corticosteroids in pregnancy. In the pregnant woman these may include, pain at the injection site, the onset of gestational diabetes, hypertension, osteoporosis, vision problems, flu-like symptoms like sore throat, fever and chills.
In the fetus, the following side effects are possible: low birth weight, cleft palate, adrenal suppression and a greater risk of infection in the first 12 months of life.
The corticosteroid dexamethasone is no longer used due to side effects such as oligohydramnios or a deficiency of amniotic fluid, which can be life-threatening to the fetus.
IVIG can be administered with or without corticosteroids. More studies are needed to confirm the benefits and risks of potential side effects.
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