During pregnancy Antenatal management only occurs if a mother has had a previously affected baby or a family member has had an affected baby. Interventions can be classified as invasive or non-invasive. A review of the evidence has shown that invasive management resulted in a relatively high complication rate (mainly preterm emergency cesarean section) of 11% per treated pregnancy. Noninvasive management was also shown to be effective, but without the relatively high rate of adverse outcomes seen with invasive management. They concluded that first-line antenatal management in<unk>  should be non-invasive with weekly intravenous immunoglobulin administration, with or without the addition of corticosteroids. Recent international guidelines have now recommended non-invasive management of<unk> . Previously there had been no international consensus on the optimal antenatal management of<unk> , and numerous strategies had been used in different centers that specialized in antenatal treatment. Invasive management Fetal blood sampling from the umbilical cord and intrauterine platelet transfusion was the first antenatal treatment for<unk>  to prevent intracerebral hemorrhage. However, this is no longer recommended routinely because of the serious risk of harms. Cordocentesis in the presence of a low platelet count may lead to serious complications, these included slowing of the baby's heart (fetal bradycardia), tamponade of the cord, and bleeding complications in the baby, including exsanguination. Fetal blood sampling is estimated to cause death of the baby in 1.3% of procedures, however the incidence varies significantly from center to center. With an overall risk of death of the fetus due to the repeated procedures of about 3% (17 deaths out of 485 pregnancies). In addition, given the short life span of transfused platelets, transfusions are needed regularly, increasing the overall risk of death of the baby. If intrauterine platelet transfusions are performed, they are generally repeated weekly (platelet lifespan after transfusion is approximately 8 to 10 days). Platelets administered to the fetus must be negative for the culprit antigen (often -1a, as stated above). Many blood suppliers (such as American Red Cross; NHS Blood and Transplant; United Blood Services) have identified -1a and 5b negative donors. An alternative donor is a mother who is, of course, negative for the culprit antigen. However, she must meet general criteria for donation and platelets received from the mother must be washed to remove the offending alloantibody and irradiated to reduce the risk of graft-versus-host disease. If platelet transfusions are needed urgently, incompatible platelets may be used, with the understanding that they may be less effective and that the administration of any blood product carries risk. Any administered cellular blood products must be irradiated to reduce the risk of graft-versus-host disease in the fetus. Additionally, all administered blood products should be reduced-risk ( seronegative and leukoreduced are considered essentially equivalent for the purposes of risk reduction). Non-invasive management The use of Intravenous immunoglobulin () during pregnancy and immediately after birth has been shown to help reduce or alleviate the effects of in infants and reduce the severity of thrombocytopenia. The most common treatment is weekly infusions at a dosage of 1 g/kg beginning at 12 to 16 weeks of pregnancy in women who have had a previously affected child with an intracranial hemorrhage. For all other pregnancies, use of IVIG should be discussed, and, if indicated, should be started before 24 weeks of pregnancy and continued until the birth of the child. In some cases this dosage is increased to 2 g/kg and/or combined with a course of prednisolone depending on the exact circumstances of the case. In a review they found that giving IVIG alone during pregnancy prevented intracranial hemorrhage in 98.7% of treated pregnancies (4 cases occurred in 315 pregnancies). This is a similar estimate to a previous review that only assessed the evidence within randomised controlled trials. They also found no consistent benefit of adding steroids to IVIG. The goal of both and platelet transfusion is to avoid hemorrhage. Ultrasound monitoring to detect hemorrhage in the fetus is not recommended as detection of intracranial hemorrhage generally indicates permanent brain damage (there is no intervention that can be performed to reverse the damage once it has occurred). Before delivery, the fetal platelet count may not be known, due to the high risks associated with cordocentesis (see above). If the platelet count is not known then assisted forms of delivery, for example forceps or ventouse, should be avoided to reduce the risk of harm. If the delivery has been planned then antigen negative platelets should be available in case the infant's platelet count is low on a cord blood sample. After birth The most rapidly effective treatment in infants with severe hemorrhage and/or a very low platelet count (−1) is the transfusion of compatible platelets (i.e. platelets from a donor who, like the mother, lacks the causative antigen). If antigen negative platelets are unavailable, then standard<unk>  platelet transfusions should be given until antigen negative platelets become available. If a platelet transfusion is not available immediately then the infant can be given IVIG (1g/kg) however, this will have no effect on the platelet count before 24 to 72 hours. A platelet transfusion is required immediately if there is severe or life-threatening bleeding. If life-threatening bleeding occurs, for example an intracranial hemorrhage, then the platelet count needs to be increased to decrease the risk of further bleeding (> 100,000 μL−1). Any infant with suspected<unk>  should have an ultrasound of the head within the first 24 hours after birth to make sure that there is no evidence of an intracranial hemorrhage. If the infant has a platelet count >30,000 μL−1 and no evidence of bleeding, then the baby can be monitored with blood counts until the blood counts return to normal, without the need for any additional treatment. In the past, infusions of (1 g/kg/day for two days) have been given to the infant and have been shown to rapidly increase the platelet count. However, IVIG and platelet transfusions are also associated with harm and therefore should be avoided if they are not necessary. After a first affected pregnancy, if a mother has plans for a subsequent pregnancy, then the mother and father should be typed for platelet antigens and the mother screened for alloantibodies. Testing is available through reference laboratories (such as ). testing of the father can be used to determine zygosity of the involved antigen and therefore risk to future pregnancies (if homozygous for the antigen, all subsequent pregnancies will be affected, if heterozygous, there is an approximate 50% risk to each subsequent pregnancy). During subsequent pregnancies, the genotype of the fetus can also be determined using amniotic fluid analysis or maternal blood as early as 18 weeks gestation to definitively determine the risk to the fetus.
Neonatal alloimmune thrombocytopenia
Gestational thrombocytopenia
X linked thrombocytopenia
Quebec platelet disorder
Congenital amegakaryocytic thrombocytopenia
Gray platelet syndrome
Severe fever with thrombocytopenia syndrome
Harris platelet syndrome