Thrombocytopenia: A reduced level of platelets, a specialized kind of blood cell.
Normal Lab Values: <150 x 10 9/L. This value is the same regardless of age.
Thrombocytopenia is another lesser-known complication of HDFN, affecting 26% of fetuses 1 and infants 2. The child’s body is so busy producing red blood cells to compensate for the ones destroyed by the antibodies, that it simply does not produce other blood cells including white blood cells (neutrophils), and platelets (thrombocytes) 3. This can lead to thrombocytopenia – a low level of platelets. Risk factors include IUTs, small for gestational age, and lower gestational age at birth. Hydropic infants are more likely to be thrombocytopenic, though thrombocytopenia occurs in non-hydropic infants as well. Infants with thrombocytopenia experience bruising and bleeding easier than other infants. For the majority of infants, this is just monitored with occasional blood draws and diligence about bumps and bruises. In severe cases, platelet transfusions are utilized. “Thrombocytopenia is an independent risk factor for perinatal mortality. Mortality in fetuses that were severely thrombocytopenic and severely hydropic was 67%.” 1
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