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840 Risk Factors of Neonatal Immune Thrombocytopenia in Pregnant Women Previously Diagnosed with ITP: Results from a French Nationwide Prospective Study

Program: Oral and Poster Abstracts
Session: 311. Disorders of Platelet Number or Function: Poster I
Hematology Disease Topics & Pathways:
Diseases, Pediatric, Pregnancy, Immune Disorders, Study Population
Saturday, December 5, 2020, 7:00 AM-3:30 PM

Stephanie Guillet1*, Valentine Loustau2*, Anissa Zarour3*, Emmanuelle Boutin, MD4*, Thibault Comont5*, Odile Souchaud-Debouverie6*, Nathalie Costedoat-Chalumeau, MD, PhD7*, Brigitte pan-Petesch, MD8*, Delphine Gobert, M.D9*, Stephane Cheze, MD10*, Jean-Francois Viallard11*, Anne-Sophie Morin12*, Gaetan Sauvetre13*, Manuel Cliquennois, MD, MSc14*, Bruno Royer, MD15*, Corinne Haioun, MD PhD16, Agathe Masseau17*, Louis Terriou18*, Claire Fieschi, MD, PhD19*, Matthieu Mahevas20*, Marc Michel21* and Bertrand Godeau21*

1Department of Internal Medecine, Henri Mondor University Hospital, Creteil, FRA
2Department of Internal Medecine, Henri Mondor University Hospital, Creteil, France
3Henri Mondor University Hospital, Creteil, France
4Department of Public Health and Biostatistics, Henri Mondor Hospital, Créteil, France
5Service de médecine interne, IUCT Oncopole, Centre Hospitalier Universitaire de Toulouse, Toulouse, France
6Department of Internal Medecine, Miletrie University Hospital, Poitiers, France
7Department of Internal Medecine, Cochin University Hospital, Paris, FRA
8Haemophilia Treatment Centre, CHRU Brest, Brest, France
9Internal Medicine, Saint Antoine Hospital, Paris, France
10Service d'Hématologie Clinique, CHU Côte de Nacre, Caen, France
11Haut-Leveque Hospital, Pessac, FRA
12Department of Internal Medicine, Bondy Hospital, Bondy, FRA
13Department of Internal Medecine, Charles-Nicolle University Hospital, Rouen, France
14Hôpital Saint Vincent De Paul, Lille Cedex, FRA
15Department of Immuno hematology, Hôpital Saint-Louis, Assistance Publique – Hôpitaux de Paris, Paris, France
16Clinical Hematology, Henri Mondor University Hospital, UPEC, Creteil, France
17Department of Internal Medecine, Hotel Dieu Hospital, Nantes, France
18Hôpital Claude Huriez, Lille, France
19Service d’Immunologie clinique, Hôpital Saint-Louis, AP-HP, Paris, France
20Service de Médecine Interne, Centre national de référence des cytopénies auto-immunes de l’adulte, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, Assistance Publique Hôpitaux de Paris, Université Paris Est Créteil, 94000 Créteil, Creteil, France
21Service de Médecine Interne, Centre national de référence des cytopénies auto-immunes de l’adulte, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, Assistance Publique Hôpitaux de Paris, Université Paris Est Créteil, 94000 Créteil, Créteil, France

Background: Neonatal immune thrombocytopenia (NITP) is a well described complication in newborns of women with ITP. It is reported to occur in about 15% to 30% of neonates. Previous pregnancies with NITP or ITP refractory to splenectomy have been described as associated with NITP mostly in retrospective studies. Methods: We conducted a nationwide prospective multicenter observational case-control study (ClinicalTrials.gov NCT02892630). Thirty-three centers including in the network of ITP experts in France participated in the study. Over a two years period, we enrolled 180 pregnant women with a history of ITP diagnosed before pregnancy and 171 of them were followed up until the delivery. Neonatal platelet counts were available for 136 newborns. Risk factor for developing NITP were evaluated as well as NITP treatment and complications. Results: NITP defined as a platelet count < 100 x 109/L was observed in 37 newborns (27.2%). More severe NITP with platelet counts < 50 x 109/L and < 30 x 109/L, were reported in 19 (14%) and 13 (9.6%) newborns respectively. Intravenous immune globulins were given to 18 newborns. Their median platelet count was 25.5 x 109/L (6; 56). Platelet transfusion was used for 8 newborns with a median platelet count of 13.5 x 109/L (6; 50). NITP was complicated by a hemorrhagic event in only 2 newborns, with a fatal bleeding in 1. Decline in disease ITP status in the mother during pregnancy and previous history of NITP were identified as predictors of NITP < 50 x 109/L by a univariate analysis while only previous history of NITP was confirmed in multivariate analysis (adjusted odds ratio (OR) 4.55; 95% confidence interval (CI) 1.48-13.92; p= 0.008). Decline in ITP disease status in the mother during pregnancy was the sole predictive factor for severe NITP defined as platelet < 30 x 109/L in multivariate analysis (adjusted OR 3.99; 95% CI 1.04-15.36; p = 0.044). Conclusion: Our study confirms that for ITP women with several pregnancies, a previous history of NITP is a risk factor for NITP. We also identify for the first time worsening of disease status during pregnancy to be a novel risk factor of severe NITP. In contrast, we did not confirm that a history of splenectomy was associated with an increased risk of NITP as suggested in retrospective studies (Loustau et al, Br J Haematol 2014; 166 929-35). Our results support that pregnancy in women with ITP is associated with an acceptable risk of severe bleeding in the newborn with NITP which is low but yet existing. Hence, close monitoring of pregnancy and delivery of mothers with ITP and their newborns is required, mainly in women who have a previous history of NITP or experienced a worsening of ITP during the pregnancy.

Disclosures: Haioun: Takeda: Honoraria; Novartis: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Roche: Honoraria; Servier: Honoraria; Miltenyi: Honoraria. Mahevas: GSK: Research Funding. Michel: Rigel: Consultancy; Bioverativ: Consultancy; Alexion Pharmaceuticals: Consultancy. Godeau: Novartis: Honoraria; Amgen: Honoraria; Amgen: Research Funding; LFB: Honoraria.

*signifies non-member of ASH