Thrombocytopenia during pregnancy


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Thrombocytopenia during pregnancy

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Thrombocytopenia during pregnancy

  1. 1. Thrombocytopenia during pregnancy Prof. Aboubakr Elnashar Benha University Hospital, Egypt Aboubakr Elnashar
  2. 2. Causes of thrombocytopenia in pregnancy  Spurious result (reduced platelets on automated Coulter counter because of platelet clumping or misreading of large immature platelets as red cells)  Gestational thrombocytopenia  ITP  PET and Haemolysis, HELLP syndrome  DIC  Sepsis  Haemolytic uraemic syndrome (HUS)/thrombotic thrombocytopenic purpura (TTP) HIV, drugs and infections (e.g. malaria) SLE and APS Bone marrow suppression. Aboubakr Elnashar
  3. 3. Incidence 5-10% of pregnant women Pregnancy-associated’ or ‘gestational’ thrombocytopenia: 75% Chronic ITP:  usually affects young women (female to male ratio = 3:1) quite commonly encountered in pregnancy 1- 2 in 10,000 pregnancies. Aboubakr Elnashar
  4. 4. Alloimmune thrombocytopenia fetal disorder caused by fetomaternal incompatibility for platelet antigens (similar to Rhesus haemolytic disease of the newborn). no maternal symptoms and the mother is not thrombocytopenic. The condition develops in utero affects all children including the firstborn, but is usually (except in the case of subsequent siblings) diagnosed after birth. The incidence: 1 in 2000 10% of all cases of neonatal thrombocytopenia. Aboubakr Elnashar
  5. 5. Clinical features Gestational thrombocytopenia benign condition even if the platelet count falls to <100 × 109/L: no adverse consequences for mother or baby. Aboubakr Elnashar
  6. 6. ITP: Haemorrhage is unlikely with platelet counts >50 × 109/L  spontaneous haemorrhage without surgery is unlikely with counts >20 × 109/L. Patients may present with skin bruising or gum bleeding, but severe haemorrhage is rare. isolated thrombocytopenia without any associated haematological abnormality. no splenomegaly or lymphadenopathy. Aboubakr Elnashar
  7. 7. Thrombocytopenia in the first half of pregnancy  less likely to be due to the pregnancy itself and should alert the clinician to a possible diagnosis of ITP. Aboubakr Elnashar
  8. 8. Pathogenesis Gestational thrombocytopenia The platelet count tends to fall progressively during normal pregnancy  in 5% to 10% of women the count will reach thrombocytopenic levels (50–150 × 109/L) by term. Aboubakr Elnashar
  9. 9. ITP Autoantibodies against platelet surface antigens: peripheral platelet destruction by the reticuloendothelial system, particularly the spleen. Aboubakr Elnashar
  10. 10. Diagnosis ITP By exclusion of other causes of thrombocytopenia, e,g. infection, PET  Bone marrow: normal or megakaryocytic bone marrow examination is not necessary in pregnancy in cases of isolated thrombocytopenia unless it is severe (platelet count <30 × 109/L). Antiplatelet antibody determination: not readily available not helpful in the diagnosis of ITP in pregnancy {absence of antiplatelet antibodies does not exclude the diagnosis of ITP}. Aboubakr Elnashar
  11. 11. Effect of pregnancy on ITP No effect on the course of ITP Anxieties arise around the time of delivery{possible bleeding associated with vaginal and abdominal delivery and regional anaesthesia and analgesia}. Aboubakr Elnashar
  12. 12. Effect of ITP on pregnancy Maternal: Capillary bleeding and purpura: unlikely with a platelet count of >50 × 109/L, spontaneous mucous membrane bleeding: not a risk with platelet counts >20× 109/L. Aboubakr Elnashar
  13. 13. Foetal: Antiplatelet IgG can cross the placenta: fetal thrombocytopenia. Accurate prediction of the fetal platelet count from maternal platelet count antibody level or splenectomy status is not possible: it is difficult to predict which fetuses will be affected. The level of risk to the fetus, which has been overestimated in older studies, is small, in contrast to the fetal risk in alloimmune thrombocytopenia The risk of fetal platelet counts <50 × 109/L: 5%- 10% 10–15% in women known to have ITP before pregnancy and in those with symptomatic ITP in the index pregnancy. Aboubakr Elnashar
  14. 14. The incidence of antenatal or neonatal intracranial haemorrhage in women with ITP:  0% to 1.5% lowest in the absence of maternal symptoms or a history of ITP prior to the index pregnancy. Best predictors of severe neonatal thrombocytopenia: previously affected child, and the incidence of serious haemorrhage in the fetus and neonate is low. Aboubakr Elnashar
  15. 15. Management Gestational thrombocytopenia benign condition requires no intervention. Aboubakr Elnashar
  16. 16. ITP Maternal considerations  Exclude associated conditions such as SLE or APS. The platelet count monitored: monthly and then more frequently in the third trimester: therapy can be instituted if required prior to delivery. Treatment is only required in the first and third trimesters if: – The woman is symptomatic with bleeding – The platelet count is <20 × 109/L – The count needs to be increased prior to a procedure such as CVS. Aboubakr Elnashar
  17. 17. Counts<50×109/L: even in the absence of bleeding prophylactic treatment prior to delivery. Counts 50 to 80×109/L: treatment prior to delivery in order to facilitate safe administration of regional analgesia/anaesthesia. CS: only required for obstetric indications Epidural and spinal anaesthesia: safe with stable counts >75 to 80 × 109/L. Bleeding time: does not predict haemorrhage and is not indicated. Aboubakr Elnashar
  18. 18. Corticosteroids: first-line therapy Dose: •outside pregnancy: high doses (60–80 mg/day, 1 mg/kg/day) of prednisolone are usually given for newly diagnosed ITP •in pregnancy: lower doses (20–30 mg/day), which are safe and effective. •Following this, the dose may be weaned to the lowest that will maintain a satisfactory (>50 × 109/L) maternal platelet count. Aboubakr Elnashar
  19. 19. Anti-D immunoglobulin therapy given as an intravenous bolus raise platelet counts in non-splenectomised rhesus-positive women. by creating a decoy to competitively inhibit the destruction of antibody-coated platelets.  Doses: 50 to 70 g/kg. safe and effective in the second and third trimesters. The baby should be monitored for neonatal jaundice, anaemia, and direct antiglobulin test positivity after delivery. Aboubakr Elnashar
  20. 20. Splenectomy should be avoided in pregnancy if possible may be necessary in extreme cases. Ideally it should be performed in the second trimester can at this stage be performed laparoscopically. Women with ITP who have previously been treated with splenectomy should continue penicillin prophylaxis throughout pregnancy. Aboubakr Elnashar
  21. 21. Other options for women who fail to respond to oral prednisolone and IVIg: i.v. methylprednisolone azathioprine or ciclosporin. Although not recommended, danazol and vincristine have been successfully used for severe resistant cases in pregnancy. Aboubakr Elnashar
  22. 22. Platelet transfusions as a last resort for bleeding or prior to surgery will increase antibody titres and do not result in a sustained increase in platelet counts. Aboubakr Elnashar
  23. 23. Fetal considerations Transfer of IgG increases at the end of pregnancy and the baby is not at risk of bleeding before labour and delivery: no place for serial fetal blood samples earlier in gestation. CS: only indicated for obstetric reasons {No evidence that CS reduces the incidence of ICH, or that it is less traumatic for the fetus than vaginal delivery. The risk of fetal blood sampling via cordocentesis (cord spasm, haemorrhage from the cord puncture site) is similar (or even higher in thrombocytopenic fetuses) to the risk of intracerebral haemorrhage (ICH). Aboubakr Elnashar
  24. 24. Neonate: Cord platelet count determined immediately after delivery  platelet count only reaches a nadir after two to five days in affected infants {when splenic circulation is established}: most hemorrhagic events occur 24 to 48 hs after delivery at the nadir of the platelet count: monitoring is necessary over this time. IVIg indications Bleeding severe thrombocytopenia platelet count of the cord blood is low (<20 × 109/L). Aboubakr Elnashar
  25. 25. Immune thrombocytopenia The diagnosis of ITP is one of exclusion and should only be made once other causes of thrombocytopenia have been excluded. Bleeding is unlikely if the platelet count is >50 × 109/L. The risk of serious thrombocytopenia and haemorrhage in the neonate from transplacental passage of antiplatelet IgG is low. CS is only required for obstetric indications Epidural and spinal anaesthesia/analgesia are safe with stable counts >75 to 80 × 109/L. Treatment, if required, should be with corticosteroids or IVIg. Aboubakr Elnashar
  26. 26. ThankYou Aboubakr Elnashar