Management Of Fetomaternal Alloimmune Thrombocytopenia Research Articles

Fetal and neonatal alloimmune thrombocytopenia.

Fetomaternal alloimmune thrombocytopenia (FMAIT) is a relatively uncommon disease, but is the leading cause of severe thrombocytopenia in the newborn. It can cause severe complications and long-term disabilities. The main objective of screening is to reduce both the morbidity and mortality associated with FMAIT, primarily by preventing intracranial hemorrhage. However, controversy surrounds both pre- and antenatal management. This article discusses pathogenesis, screening, diagnosis, and both pre- and neonatal management of FMAIT.

Antenatal interventions for fetomaternal alloimmune thrombocytopenia

Fetomaternal alloimmune thrombocytopenia results from the formation of antibodies by the mother which are directed against a fetal platelet alloantigen inherited from the father. The resulting fetal thrombocytopenia (reduced platelet numbers) may cause bleeding, particularly into the brain, before or shortly after birth. Antenatal treatment of fetomaternal alloimmune thrombocytopenia includes the administration of intravenous immunoglobulin (IVIG) and/or corticosteroids to the mother to prevent severe fetal thrombocytopenia. IVIG and corticosteroids both have short-term and possibly long-term side effects. IVIG is also costly and optimal regimens need to be identified. To determine the optimal antenatal treatment of fetomaternal alloimmune thrombocytopenia to prevent fetal and neonatal haemorrhage and death. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2011) and bibliographies of relevant publications and review articles. Randomised controlled studies comparing any intervention with no treatment, or comparing any two interventions. Two review authors independently assessed eligibility, trial quality and extracted data. We included four trials involving 206 people. One trial involving 39 people compared a corticosteroid (prednisone) versus IVIG alone. In this trial, where analysable data were available, there was no statistically significant differences between the treatment arms for predefined outcomes. Three trials involving 167 people compared IVIG plus a corticosteroid (prednisone in two trials and dexamethasone in one trial) versus IVIG alone. In these trials there was no statistically significant difference in the findings between the treatment arms for predefined outcomes (intracranial haemorrhage; platelet count at birth and preterm birth). Lack of complete data sets and important differences in interventions precluded the pooling of data from these trials. The optimal management of fetomaternal alloimmune thrombocytopenia remains unclear. Lack of complete data sets for two trials and differences in interventions precluded the pooling of data from these trials which may have enabled a more developed analysis of the trial findings. Further trials would be required to determine optimal treatment (the specific medication and its dose and schedule). Such studies should include long-term follow up of all children and mothers.

HPA‐1a antibody potency and bioactivity do not predict severity of fetomaternal alloimmune thrombocytopenia

The antenatal management of fetomaternal alloimmune thrombocytopenia (FMAIT) due to HPA-1a antibodies remains controversial, and a test identifying pregnancies that do not require therapy would be of clinical value. The statistical correlation was analyzed between clinical outcome and 1) anti-HPA-1a potency in maternal serum samples determined by a monoclonal antibody immobilization of platelet (PLT) antigen assay with an international anti-HPA-1a potency standard and 2) anti-HPA-1a biological activity measured by a monocyte chemiluminescence (CL) assay. A total of 133 pregnancies with FMAIT due to anti-HPA-1a were analyzed. In 97 newly diagnosed cases, there was no difference in antibody potency or CL signal between cases with intracranial hemorrhage (ICH; n = 15), those with no ICH but a PLT count of less than 20 x 10(9) per L (n = 52), and those with a PLT count of at least 20 x 10(9) per L (n = 30). In 22 previously known pregnancies, the positive predictive value of maternal anti-HPA-1a of greater than 30 IU per mL for a PLT count of less than 20 x 10(9) per L was 90 percent, but the negative predictive value was only 66 percent. Antibody potency tended to stay stable throughout pregnancy (n = 16) and from one pregnancy to the next (n = 16). Neither severe thrombocytopenia nor ICH in HPA-1a-alloimmunized pregnancies can be predicted with sufficient sensitivity and specificity for clinical application from maternal anti-HPA-1a potency or bioactivity.

Peut-on prendre en charge l'allo-immunisation plaquettaire fœtomaternelle de manière non invasive ? Expérience sur dix ans

Objectives Our purpose was to study a non-invasive management of fetomaternal alloimmune thrombocytopenia (FMAIT). Patients and methods Between 1996 and 2005, 18 women were treated. The population was divided into 2 groups: patients with a history of intracranial haemorrhage (ICH) in the older sibling received weekly intravenous immunoglobulin (IVIG) therapy to the mother (1 g/kg per week) without initial cordocentesis whereas patients with a history of neonatal thrombocytopenia did not undergo any treatment. Results All pregnancies with a previous FMAIT were monitored with serial ultrasound scans without cordecentesis. 15 patients had HPA-1, 2 HPA-3 and 1 HPA-5 immunizations. Weekly intravenous immunoglobulin therapy was administered in 5 patients with a history of ICH in the older sibling. Two of these delivered thrombocytopenic children; one had a platelet count < 50 × 10 9/l. For the 13 women (one twin) who had a sibling with neonatal thrombocytopenia, 11/14 newborns had a platelet count < 50 × 10 9/l. Predelivery fetal blood sampling were performed in 8/18 pregnancies. The neonatal periods of the 19 children were uncomplicated and no ICHs were observed. Discussion and conclusion Our results suggest that a non-invasive strategy avoiding serial cordocentesis may be an effective therapy in patients who are at risk of fetal and neonatal alloimmune thrombocytopenia.

European study of the antenatal management of fetomaternal alloimmune thrombocytopenia (FMAIT)

FMAIT occurs in ∼1 in 1200 births, of which 10–20% have serious bleeding, i.e. intracranial haemorrhage (ICH). Management of such pregnancies needs to balance the risk of bleeding against the known risk of fetal blood sampling (FBS). S tudy This was a nonrandomised observational study of FMAIT due to anti-HPA-1a. All cases were managed by an initial FBS, then a) intravenous immunoglobulin (IVIgG), b) regular intrauterine platelet transfusions (IUT), c) neither of above, but FBS ± 1 IUT predelivery, d) no treatment. All babies with a previous sibling known to have platelets < 20 × 109/L or an ICH were considered high risk. R esults 43 pregnancies (44 babies) were analysable giving 49 results in total (more than 1 management in 5). In (a) there was one case with ICH. The resultant platelet count was ≥ 50 × 109/L in 10 cases, and 6 of these were high risk (5 ICH, 1plts < 20 × 109/L). No significant side-effects of treatment occurred. In (b) the number of high risk cases was greater than (a) and there were 2 cases of ICH. The pre-IUT platelet count was < 20 × 109/L on at least 50% of occasions in 10 cases. Overall 12 babies needed to be delivered because of complications caused by FBS/IUT, 4 at less than 32 weeks gestation. There were few cases in (c) and no cases in (d). C onclusions The incidence of ICH in the study group is less than the incidence of ICH in untreated siblings. However, complications from FBS/IUT were significant, and the platelet count was not consistently maintained at > 20 × 109/L. Further studies are required to define the optimal antenatal management of FMAIT.

Investigation and management of fetomaternal alloimmune thrombocytopenia.

Investigation and management of fetomaternal alloimmune thrombocytopenia.

Inadequacies in the postnatal management of fetomaternal alloimmune thrombocytopenia (FMAIT)

93 (31%) of the 301 Haematology Departments in the U.K. responded to a questionnaire about the postnatal management of fetomaternal alloimmune thrombocytopenia (FMAIT). The number of reported cases of FMAIT was less than half than that estimated from its known incidence, suggesting that the condition is under-recognized. There was a consensus that the optimal approach to postnatal management is to transfuse compatible platelets promptly. However, a number of problems in the delivery of treatment were identified, including an apparent lack of awareness of the potential seriousness of the condition amongst clinical staff, and the availability of HPA-1a negative platelets.

Inadequacies in the postnatal management of fetomaternal alloimmune thrombocytopenia (FMAIT)

Inadequacies in the postnatal management of fetomaternal alloimmune thrombocytopenia (FMAIT)