Pregnancy and cardiovascular outcomes among patients post Fontan surgery: a 25-year single-centre retrospective cohort study.

Introduction: Data on the characteristics and outcomes of pregnancy and among patients with Fontan physiology are limited. We aimed to evaluate the immediate and long-term outcomes among these patients who were followed at our centre.

Methods: We included adult patients who had undergone Fontan surgery for congenital heart disease and were pregnant between 1994 and 2021. We examined maternal and obstetric outcomes.

Results: In a cohort of 109 patients following Fontan procedure, 51 patients were women, and 19 patients (37%) had a pregnancy during the follow-up period, accounting for a total of 46 pregnancies. Intrauterine growth retardation of the fetus was common, observed in 23% of all pregnancies and 50% of live births. The main fetal complication was prematurity, observed in 43% of all pregnancies and 90% of live birth. The maternal complications included pre-eclampsia (one patient), placental detachment (one patient), acute heart failure exacerbation (one patient), arrhythmia (three atrial arrhythmias) and major peripartum haemorrhage (two patients), with no peripartum death.

Conclusions: Over one-third of women with Fontan physiology in our cohort had a documented pregnancy. Maternal and obstetric complications were common among these patients, and expanded long-term data is needed. Limitations, including small sample size and survival bias, may have underestimated the risk of adverse outcomes in this cohort.