Bleeding and thrombotic risk in pregnant women with Fontan physiology

Andrea Girnius, Dominica Zentner, Anne Marie Valente, Petronella G. Pieper, Katherine E. Economy, Magalie Ladouceur, Jolien W. Roos-Hesselink, Carri Warshak, Sara L. Partington, Zhiqian Gao, Nicholas Ollberding, Michelle Faust, Saulius Girnius, Harald Kaemmerer, Nicole Nagdyman, Scott Cohen, Mary Canobbio, Teiji Akagi, Jasmine Grewal, Elisa BradleyYonathan Buber, Joseph Palumbo, Niki Walker, Jamil Aboulhosn, Erwin Oechslin, Helmut Baumgartner, Wesam Kurdi, Wendy M. Book, Barbara J.M. Mulder, Gruschen R. Veldtman*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

10 Citations (Scopus)


Background/objectives Pregnancy may potentiate the inherent hypercoagulability of the Fontan circulation, thereby amplifying adverse events. This study sought to evaluate thrombosis and bleeding risk in pregnant women with a Fontan. Methods We performed a retrospective observational cohort study across 13 international centres and recorded data on thrombotic and bleeding events, antithrombotic therapies and pre-pregnancy thrombotic risk factors. Results We analysed 84 women with Fontan physiology undergoing 108 pregnancies, average gestation 33±5 weeks. The most common antithrombotic therapy in pregnancy was aspirin (ASA, 47 pregnancies (43.5%)). Heparin (unfractionated (UFH) or low molecular weight (LMWH)) was prescribed in 32 pregnancies (30%) and vitamin K antagonist (VKA) in 10 pregnancies (9%). Three pregnancies were complicated by thrombotic events (2.8%). Thirty-eight pregnancies (35%) were complicated by bleeding, of which 5 (13%) were severe. Most bleeds were obstetric, occurring antepartum (45%) and postpartum (42%). The use of therapeutic heparin (OR 15.6, 95% CI 1.88 to 129, p=0.006), VKA (OR 11.7, 95% CI 1.06 to 130, p=0.032) or any combination of anticoagulation medication (OR 13.0, 95% CI 1.13 to 150, p=0.032) were significantly associated with bleeding events, while ASA (OR 5.41, 95% CI 0.73 to 40.4, p=0.067) and prophylactic heparin were not (OR 4.68, 95% CI 0.488 to 44.9, p=0.096). Conclusions Current antithrombotic strategies appear effective at attenuating thrombotic risk in pregnant women with a Fontan. However, this comes with high (>30%) bleeding risk, of which 13% are life threatening. Achieving haemostatic balance is challenging in pregnant women with a Fontan, necessitating individualised risk-adjusted counselling and therapeutic approaches that are monitored during the course of pregnancy.

Original languageEnglish
Pages (from-to)1390-1397
Number of pages8
Issue number17
Early online date12 Aug 2021
Publication statusPublished - 24 Nov 2021

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© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.


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