The Fontan operation is a surgical procedure performed in infants with congenital cardiac malformations with a single ventricle physiology that is only amenable to univentricular repair. This procedure allows systemic venous blood from the vena cava to flow directly to the pulmonary arteries, bypassing the right ventricle, thus creating a total cavopulmonary circulation, where the left ventricle still pumps blood systemically. Over time, this surgical procedure has been refined, allowing for a greater number of these individuals to survive to reproductive age. There are pronounced physiological haemodynamic changes which occur during pregnancy and labour including reduced peripheral vascular resistance, and increased blood volume, cardiac output, left ventricular stroke work and oxygen consumption. Patients with Fontan circulation are often unable to cope with these haemodynamic changes, which may lead to a number of complications. These include obstetric complications such as miscarriage, preterm labour and preterm premature rupture of membranes; neonatal complications such as prematurity and intrauterine growth restriction; cardiac complications such as intracardiac thrombosis, arrhythmia, heart failure and stroke; and haematological complications such as venous thromboembolism. We describe the case of a 17 year old primiparous female who underwent a staged Fontan operation by the age of 3 years for congenital transposition of the great arteries and a large ventricular septal defect. She had an unplanned pregnancy which was booked and initially managed at a rural hospital, followed by transfer to a tertiary hospital for antepartum haemorrhage and threatened preterm labour at 31 weeks gestation. During the course of the pregnancy, she had recurrent episodes of antepartum haemorrhage and was diagnosed to have fetal growth restriction. She was managed in close collaboration between obstetricians, cardiologists, anaesthetists and neonatologists and had a successful vaginal delivery at 36 weeks gestation after induction of labour for preterm premature rupture of membranes. The placental histopathology was suggestive of decidual vasculopathy. The patient was discharged home with her baby in good condition.