Abstract
BACKGROUND: Pregnancy in patients with congenital heart disease, particularly those with Fontan physiology, presents significant risks for both the mother and fetus. CASE SUMMARY: We present a 26-year-old woman with a history of tricuspid atresia palliated with a modified fenestrated lateral tunnel Fontan, with a successful pregnancy and delivery despite numerous challenges. She was closely monitored with monthly cardio-obstetrics follow-ups, anticoagulation therapy, echocardiography, and regular obstetric ultrasounds. At 31 weeks of gestation, the patient experienced a massive placental abruption, necessitating an emergent caesarean section. Both the patient and her baby recovered well postpartum owing to meticulous predelivery planning. DISCUSSION: The Fontan procedure, which reroutes venous blood flow directly to the pulmonary arteries via passive flow, creates unique challenges during pregnancy because of altered circulatory dynamics. There is a high risk for both thrombotic and bleeding complications as well as preterm delivery, as this case represents. Specialized cardio-obstetrics monitoring with a multidisciplinary approach was essential for optimizing outcomes despite the emergent nature of her delivery. TAKE-HOME MESSAGE: Although pregnancy may be feasible with expert care, the long-term impact on Fontan function remains uncertain and potentially adverse.