A POPULATION-BASED DATA LINKAGE APPROACH TO STUDY FETAL AND NEONATAL ALLOIMMUNE THROMBOCYTOPENIA: OVERCOMING DATA FRAGMENTATION
Author(s)
Eleonor Tiblad, MD PhD1, Valgerdur Árnadóttir, MD2, Kelvin Kwok, PhD3, Yangjun Liu, MD PhD3, Rebecca Zaha, MPH4, Jeremy Smith, MPH5, Agneta Wikman, MD PhD1, Emöke Deschmann, MD PhD1.
1Karolinska Institutet, Stockholm, Sweden, 2Karolinska University Hospital, Stockholm, Sweden, 3Ciencia Research, Stockholm, Sweden, 4Janssen, Springhouse, PA, USA, 5Johnson & Johnson, Spring House, PA, USA.
1Karolinska Institutet, Stockholm, Sweden, 2Karolinska University Hospital, Stockholm, Sweden, 3Ciencia Research, Stockholm, Sweden, 4Janssen, Springhouse, PA, USA, 5Johnson & Johnson, Spring House, PA, USA.
OBJECTIVES: Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare condition where pregnant women develop alloantibodies targeting paternally inherited platelet antigens in the fetus. In severe cases, FNAIT may lead to life-threatening intracranial hemorrhage (ICH). There is no antenatal screening for anti-platelet alloantibodies, hence prevention is only possible in at-risk pregnancies with known FNAIT history. Real world evidence (RWE) to guide clinical management remains limited due to the rarity of the condition, lack of key diagnostic and treatment variables in registers, and challenges in reliably linking maternal and neonatal data. This study aims to identify and utilize Swedish real-world data (RWD) sources and linkage strategies necessary for robust real-world evidence generation in FNAIT.
METHODS: Complementary Swedish RWD sources were identified and harmonized, including (1) nationwide population-based registers, (2) national quality registers for perinatal care, and (3) electronic medical records (EMR) and hospital laboratory databases. This study has been approved by the Swedish Ethics Review Authority.
RESULTS: Women seropositive for platelet alloantibodies with a history of FNAIT pregnancy were ascertained using EMR and laboratory test results from Karolinska Hospital, the national referral center for FNAIT, between 2000-2025. At-risk pregnancies were identified through deterministic mother-child linkage within the Medical Birth Register. Data on adverse pregnancy outcomes, bleeding events, neonatal morbidity and mortality, and healthcare resource utilization (HRU) were obtained through linkage with additional population-based and quality registers. Granular information on maternal platelet type, antenatal treatment with intravenous immunoglobulin and neonatal platelet counts were supplemented through linkage with EMRs.
CONCLUSIONS: This is one of the largest studies on FNAIT to date in Europe, demonstrating the potential of Swedish RWD in generating comprehensive clinical insights on pregnancies at risk of rare disorders. The data access route may serve as a guide for future studies on similar rare indications in Nordic countries and beyond.
METHODS: Complementary Swedish RWD sources were identified and harmonized, including (1) nationwide population-based registers, (2) national quality registers for perinatal care, and (3) electronic medical records (EMR) and hospital laboratory databases. This study has been approved by the Swedish Ethics Review Authority.
RESULTS: Women seropositive for platelet alloantibodies with a history of FNAIT pregnancy were ascertained using EMR and laboratory test results from Karolinska Hospital, the national referral center for FNAIT, between 2000-2025. At-risk pregnancies were identified through deterministic mother-child linkage within the Medical Birth Register. Data on adverse pregnancy outcomes, bleeding events, neonatal morbidity and mortality, and healthcare resource utilization (HRU) were obtained through linkage with additional population-based and quality registers. Granular information on maternal platelet type, antenatal treatment with intravenous immunoglobulin and neonatal platelet counts were supplemented through linkage with EMRs.
CONCLUSIONS: This is one of the largest studies on FNAIT to date in Europe, demonstrating the potential of Swedish RWD in generating comprehensive clinical insights on pregnancies at risk of rare disorders. The data access route may serve as a guide for future studies on similar rare indications in Nordic countries and beyond.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
RWD181
Topic
Real World Data & Information Systems, Study Approaches
Topic Subcategory
Health & Insurance Records Systems
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, Rare & Orphan Diseases