Pregnancy in women with a Fontan circulation: Short and long-term outcomes

Background: The Fontan circulation procedure is the palliative surgery of choice for patients with single ventricle physiology, many of whom are now reaching childbearing age due to advances in care. Our study examines the impact of pregnancy on women with Fontan circulation, assessing both short and long-term outcomes. Methods: We retrospectively analysed pregnancies in women with Fontan circulation at our centre from 2005 to 2023, including a matched non-pregnant, nulliparous cohort for comparison. Pregnancies lost before 18 weeks were analysed separately. Results: Among 26 pregnancies in 18 women, preterm births were common (73.1%), with 3 fetal losses and no maternal deaths. Neonatal complications included a 50% incidence of babies small for gestational age (SGA). Cardiac events occurred in 19.2% of pregnancies, primarily supraventricular arrhythmias, and 23% experienced postpartum haemorrhage. Over a median 6.1 [5.2-10.6]-year follow-up, no deaths, heart failure (HF), or Fontanassociated liver disease (FALD) developed, and functional status remained stable. Conclusions: Women with a Fontan-type circulation undergoing pregnancy had a few serious maternal cardiac events, though there was a high rate of post-partum haemorrhage. The rates of neonatal complications, particularly related to restricted growth and pre-term birth, were also high. Our findings indicate a generally positive medium-term outlook for these patients, though the impact of pregnancy on long-term survival remains unclear. Careful selection of patients with Fontan circulation during pre-pregnancy counselling may help to reduce complications during and after pregnancy.