title: The incidence and outcomes of fetomaternal alloimmune thrombocytopenia: a UK national study using three data sources.
abstract: Fetomaternal alloimmune thrombocytopenia (FMAIT) is the most common cause of severe neonatal thrombocytopenia in otherwise well, term infants. First pregnancies are often severely affected. This descriptive, population-based national study was undertaken in order to inform the case for antenatal screening. Cases were identified using three sources and capture-recapture techniques used to generate a robust incidence estimate. One hundred and seventy three cases were identified between October 2006 and September 2008. An extra 20 cases were estimated from capture-recapture analysis, giving an estimated incidence of clinically detected FMAIT of 12·4 cases per 100 000 total births (95%confidence interval: 10·7, 14·3). Fifty-two cases (30%) were known at the start of pregnancy; 120 (70%) were unknown (n=115) or unrecognized (n=5). Unknown cases were more likely to experience a haemorrhagic complication (67% vs. 5%) (P<0·001) and more likely to have an intracranial haemorrhage (20% vs. 4%) (P=0·014) than known cases receiving antenatal management. In view of the incidence of severe disease identified, further assessment of the case for antenatal screening is important. There were a number of cases in which the significance of a history of FMAIT in a previous sibling was not recognized and there is a need to raise awareness of the importance of this diagnosis.
authors.affiliation: National Perinatal Epidemiology Unit, University of Oxford, Oxford NHS Blood and Transplant Nuffield Department of Clinical Laboratory Sciences, John Radcliffe Hospital, University of Oxford, Oxford, UK. Marian.knight@npeu.ox.ac.uk
authors.forename: Marian
authors.initials: M
authors.lastname: Knight
authors.forename: Matthias
authors.initials: M
authors.lastname: Pierce
authors.forename: Dave
authors.initials: D
authors.lastname: Allen
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Kurinczuk
authors.forename: Patsy
authors.initials: P
authors.lastname: Spark
authors.forename: David J
authors.initials: DJ
authors.lastname: Roberts
authors.forename: Michael F
authors.initials: MF
authors.lastname: Murphy
mesh_terms: D005260:Female; D005865:Gestational Age; D006470:Hemorrhage / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D010976:Platelet Count; D011159:Population Surveillance; D011247:Pregnancy; D011256:Pregnancy Outcome; D011296:Prenatal Diagnosis; D011379:Prognosis; D054098:Thrombocytopenia, Neonatal Alloimmune / Q000175:diagnosis / Q000453:epidemiology*; D006113:United Kingdom / Q000453:epidemiology